Treated Fillers, Compositions Containing Same, and Articles Prepared Therefrom

ABSTRACT

The present invention includes a process for producing treated filler that includes (a) treating a slurry that includes untreated filler, where the untreated filler has not been previously dried, with a treating composition that includes a treating agent, thereby forming a treated filler slurry, and (b) drying the treated filler slurry to produce treated filler. The treating agent can include a polymer having (i) at least one first group that interacts with the untreated filler and (ii) at least one second group that interacts with a rubber matrix into which the treated filler is incorporated. The present invention also is directed to treated filler prepared by the process, as well as rubber compounding compositions and tires including the treated filler.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. application Ser.No. 14/508,411, filed Oct. 7, 2014, now U.S. Pat. No. 9,688,784, issuedJun. 27, 2017, which claims the benefit of U.S. Provisional ApplicationNo. 61/887,713, filed Oct. 7, 2013, both of which are incorporatedherein by reference in their entirety.

FIELD OF THE INVENTION

The present invention is related to a process for the preparation oftreated filler, treated filler produced by the process, and compositionsand articles containing such treated filler.

BACKGROUND OF THE INVENTION

The use of silica/silane filler systems to reduce the rolling resistanceand improve the wet traction of passenger car and truck tires is knownin the art. A reduction of rolling resistance results in less fuelconsumption.

The simultaneous improvement of rolling resistance, wear, and traction,known as expanding the “magic triangle”, requires new approaches torubber composite development. Precipitated silica has played a majorrole in the emergence of the green tire, which boasts a largeimprovement in rolling resistance compared to past technologies. Thedirect crosslinking of silica (via coupling) into a highly crosslinkedpolymer matrix, while minimizing interactions between silica particles,is believed to be of vital importance to desirable dynamic mechanicalproperties of rubber used in the production of passenger car and trucktires. It has been noted that in natural rubber (typically used in theproduction of truck tires), the proteins present from natural rubberbiosynthesis can adsorb preferentially to the silica surface,interfering with the in-situ coupling reaction. Increased dumptemperatures, which might improve the coupling efficiency, have alsobeen shown to degrade natural rubber. Thus, there continues to be a needin the rubber industry for improved silica-rubber coupling materials.

Further, it has been found that the incorporation of high surface areafiller materials into rubber compositions can cause an undesirableincrease in viscosity, thereby limiting the amount of high surface areamaterial that can be included in the rubber composition due to processproblems. Thus, there is a need to treat such high surface materials(e.g., precipitated silica) with materials which can serve as to renderthe high surface materials more compatible with the polymeric matrixinto which they are being incorporated, improve processing viscosity,and prevent phase separation of the high surface materials from thepolymeric matrix.

SUMMARY OF THE INVENTION

In accordance with the present invention, there is provided a processfor producing treated filler that includes (a) treating a slurry thatincludes untreated filler, where the untreated filler has not beenpreviously dried, with a treating composition that includes a treatingagent, thereby forming a treated filler slurry; and (b) drying thetreated filler slurry to produce treated filler. The treating agent caninclude a polymer having (i) at least one first group that interactswith the untreated filler and (ii) at least one second group thatinteracts with a rubber matrix into which the treated filler isincorporated.

In accordance with the present invention, there is further provided aprocess for producing treated precipitated silica that includes (a)combining an alkali metal silicate and an acid to form a slurry thatincludes untreated silica, where the untreated silica has not beenpreviously dried; (b) treating said slurry with a treating compositionthat includes a treating agent, thereby forming a treated slurry; and(c) drying said treated slurry to produce treated precipitated silica.The treating agent can include a polymer having (i) at least one firstgroup that interacts with the untreated silica and (ii) at least onesecond group that interacts with a rubber matrix into which the treatedsilica is incorporated.

In accordance with the present invention, there is further provided aprocess for producing a treated precipitated silica that includes (a)combining an alkali metal silicate and an acid to form an untreatedslurry that includes untreated silica, where the untreated silica hasnot been previously dried; (b) drying the untreated slurry to producedried precipitated silica; (c) forming an aqueous slurry of the driedprecipitated silica with a treating composition that includes a treatingagent, and, optionally, a coupling agent and/or, optionally, anon-coupling agent to form a treated precipitated silica slurry; and (d)drying the treated precipitated silica slurry to produce a dried treatedprecipitated silica. The treating agent can include a polymer having (i)at least one first group that interacts with the untreated silica and(ii) at least one second group that interacts with a rubber matrix intowhich the treated silica is incorporated.

In accordance with the present invention, there is also provided treatedfiller prepared by the processes described herein, as well as rubbercompounding compositions including the treated filler, and a rubberarticle that includes the treated filler of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

As previously mentioned, the present invention provides a process forproducing treated filler. The process can include (a) treating a slurrythat can include untreated filler, where the untreated filler has notbeen previously dried, with a treating composition comprising a treatingagent, thereby forming a treated filler slurry; and (b) drying thetreated filler slurry to produce treated filler.

As used herein, with reference to filler (such as treated and/oruntreated filler), the term “not been previously dried” means fillerthat, prior to the treatment process, has not been dried to a moisturecontent of less than 20 percent by weight. For purposes of the presentinvention, untreated filler does not include filler that has beenpreviously dried to a moisture content of less than 20 percent by weightand then rehydrated.

As used herein, the term “filler” means an inorganic material such as aninorganic oxide that can be used in a polymer composition to improve atleast one property of the polymer. As used herein, the term “slurry”means a mixture including at least filler and water.

As used herein, the articles “a”, “an” and “the” include pluralreferents unless otherwise expressly and unequivocally limited to onereferent.

Unless otherwise indicated, all ranges or ratios disclosed herein are tobe understood to encompass any and all subranges or subratios subsumedtherein. For example, a stated range or ratio of “1 to 10” should beconsidered to include any and all subranges between (and inclusive of)the minimum value of 1 and the maximum value of 10; that is, allsubranges or subratios beginning with a minimum value of 1 or more andending with a maximum value of 10 or less, such as but not limited to 1to 6.1, 3.5 to 7.8, and 5.5 to 10.

Other than in the operating examples, or where otherwise indicated, allnumbers expressing quantities of ingredients, reaction conditions, andso forth used in the specification and claims are to be understood asmodified in all instances by the term “about”.

As used herein, molecular weight values of polymers, such as weightaverage molecular weights (Mw) and number average molecular weights(Mn), are determined by gel permeation chromatography using appropriatestandards, such as polystyrene standards.

As used herein, polydispersity index (PDI) values represent a ratio ofthe weight average molecular weight (Mw) to the number average molecularweight (Mn) of the polymer (i.e., Mw/Mn).

As used herein, the term “polymer” means homopolymers (e.g., preparedfrom a single monomer species), copolymers (e.g., prepared from at leasttwo monomer species), and graft polymers.

As used herein, the term “(meth)acrylate” and similar terms, such as“(meth)acrylic acid ester” means methacrylates and/or acrylates. As usedherein, the term “(meth)acrylic acid” means methacrylic acid and/oracrylic acid.

All documents, such as but not limited to issued patents and patentapplications, referred to herein, and unless otherwise indicated, are tobe considered to be “incorporated by reference” in their entirety.

As used herein, recitations of “linear or branched” groups, such aslinear or branched alkyl, are herein understood to include a methylenegroup or a methyl group; groups that are linear, such as linear C₂-C₃₆alkyl groups; and groups that are appropriately branched, such asbranched C₃-C₃₆ alkyl groups.

As used herein, recitations of “optionally substituted” group, means agroup including, but not limited to, alkyl group, cycloalkyl group,heterocycloalkyl group, aryl group, and/or heteroaryl group, in which atleast one hydrogen thereof has been optionally replaced or substitutedwith a group that is other than hydrogen, such as, but not limited to,halo groups (e.g., F, Cl, I, and Br), hydroxyl groups, ether groups,thiol groups, thio ether groups, carboxylic acid groups, carboxylic acidester groups, phosphoric acid groups, phosphoric acid ester groups,sulfonic acid groups, sulfonic acid ester groups, nitro groups, cyanogroups, hydrocarbyl groups (including, but not limited to, alkyl;alkenyl; alkynyl; cycloalkyl, including poly-fused-ring cycloalkyl andpolycycloalkyl; heterocycloalkyl; aryl, including hydroxyl substitutedaryl, such as phenol, and including poly-fused-ring aryl; heteroaryl,including poly-fused-ring heteroaryl; and aralkyl groups), and aminegroups, such as N(R₁₁′)(R₁₂′) where R₁₁′ and R₁₂′ are each independentlyselected, with some embodiments, from hydrogen, linear or branchedC₁-C₂₀ alkyl, C₃-C₁₂ cycloalkyl, C₃-C₁₂ heterocycloalkyl, aryl, andheteroaryl.

Some compounds that can be used with the method of the present inventioninclude groups and sub groups that can in each case be independentlyselected from hydrocarbyl and/or substituted hydrocarbyl and/orfunctional hydrocarbyl (or hydrocarbyl groups having one or morefunctional groups). As used herein, and in accordance with someembodiments, the term “hydrocarbyl” and similar terms, such as“hydrocarbyl substituent”, means linear or branched C₁-C₃₆ alkyl (e.g.,linear or branched C₁-C₁₀ alkyl); linear or branched C₂-C₃₆ alkenyl(e.g., linear or branched C₂-C₁₀ alkenyl); linear or branched C₂-C₃₆alkynyl (e.g., linear or branched C₂-C₁₀ alkynyl); C₃-C₁₂ cycloalkyl(e.g., C₃-C₁₀ cycloalkyl); C₅-C₁₈ aryl (including polycyclic arylgroups) (e.g., C₅-C₁₀ aryl); and C₆-C₂₄ aralkyl (e.g., C₆-C₁₀ aralkyl).

Representative alkyl groups include but are not limited to methyl,ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl,pentyl, neopentyl, hexyl, heptyl, octyl, nonyl and decyl. Representativealkenyl groups include but are not limited to vinyl, allyl and propenyl.Representative alkynyl groups include but are not limited to ethynyl, 1propynyl, 2-propynyl, 1-butynyl, and 2-butynyl. Representativecycloalkyl groups include but are not limited to cyclopropyl,cyclobutyl, cyclopentyl, cyclohexyl, and cyclooctyl substituents.Representative aralkyl groups include but are not limited to benzyl, andphenethyl.

The term “substituted hydrocarbyl” and similar terms, such as“functional hydrocarbyl” (or hydrocarbyl having at least one functionalgroup) as used herein means a hydrocarbyl group in which at least onehydrogen thereof has been substituted with a group that is other thanhydrogen, such as, but not limited to, halo groups, hydroxyl groups,ether groups, thiol groups, thio ether groups, carboxylic acid groups,carboxylic acid ester groups, phosphoric acid groups, phosphoric acidester groups, sulfonic acid groups, sulfonic acid ester groups, nitrogroups, cyano groups, hydrocarbyl groups (e.g., alkyl, alkenyl, alkynyl,cycloalkyl, aryl, and aralkyl groups), heterocycloalkyl groups,heteroaryl groups, and amine groups, such as —N(R₁₁′)(R₁₂′) where R₁₁′and R₁₂′ are each independently selected from hydrogen, hydrocarbyl andsubstituted hydrocarbyl.

The term “alkyl” as used herein, in accordance with some embodiments,means linear or branched alkyl, such as but not limited to, linear orbranched C₁-C₂₅ alkyl, or linear or branched C₁-C₁₀ alkyl, or linear orbranched C₂-C₁₀ alkyl. Examples of alkyl groups from which the variousalkyl groups of the present invention can be selected from, include, butare not limited to, those recited previously herein. Alkyl groups of thevarious compounds of the present invention can, with some embodiments,include one or more unsaturated linkages selected from —CH═CH— groupsand/or one or more —C≡C— groups, provided the alkyl group is free of twoor more conjugated unsaturated linkages. With some embodiments, thealkyl groups are free of unsaturated linkages, such as CH═CH groups and—C≡C— groups.

The term “cycloalkyl” as used herein, in accordance with someembodiments, means groups that are appropriately cyclic, such as but notlimited to C₃-C₁₂ cycloalkyl (including, but not limited to, cyclicC₅-C₇ alkyl) groups. Examples of cycloalkyl groups include, but are notlimited to, those recited previously herein. The term “cycloalkyl” asused herein in accordance with some embodiments also includes bridgedring polycycloalkyl groups (or bridged ring polycyclic alkyl groups),such as but not limited to bicyclo[2.2.1]heptyl (or norbornyl) andbicyclo[2.2.2]octyl; and fused ring polycycloalkyl groups (or fused ringpolycyclic alkyl groups), such as, but not limited to,octahydro-1H-indenyl, and decahydronaphthalenyl.

The term “heterocycloalkyl” as used herein, in accordance with someembodiments, means groups that are appropriately cyclic (having at leastone heteroatom in the cyclic ring), such as but not limited to C₃-C₁₂heterocycloalkyl groups or C₅-C₇ heterocycloalkyl groups, and which haveat least one hetero atom in the cyclic ring, such as, but not limitedto, O, S, N, P, and combinations thereof. Examples of heterocycloalkylgroups include, but are not limited to, imidazolyl, tetrahydrofuranyl,tetrahydropyranyl, and piperidinyl. The term “heterocycloalkyl” as usedherein, in accordance with some embodiments, also includes bridged ringpolycyclic heterocycloalkyl groups, such as but not limited to7-oxabicyclo[2.2.1]heptanyl; and fused ring polycyclic heterocycloalkylgroups, such as but not limited to octahydrocyclopenta[b]pyranyl, andoctahydro 1H isochromenyl.

As used herein, and in accordance with some embodiments, the term “aryl”includes C₅-C₁₈ aryl, such as C₅-C₁₀ aryl (and includes polycyclic arylgroups, including polycyclic fused ring aryl groups). Representativearyl groups include, but are not limited to, phenyl, naphthyl,anthracynyl, and triptycenyl.

The term “heteroaryl”, as used herein, in accordance with someembodiments, means aryl groups having at least one heteroatom in thering, and includes but is not limited to C₅-C₁₈ heteroaryl, such as butnot limited to C₅-C₁₀ heteroaryl (including fused ring polycyclicheteroaryl groups) and means an aryl group having at least one heteroatom in the aromatic ring, or in at least one aromatic ring in the caseof a fused ring polycyclic heteroaryl group. Examples of heteroarylgroups include, but are not limited to, furanyl, pyranyl, pyridinyl,isoquinoline, and pyrimidinyl.

As used herein, the term “fused ring polycyclic-aryl-alkyl group” andsimilar terms, such as fused ring polycyclic-alkyl-aryl group, fusedring polycyclo-aryl-alkyl group, and fused ring polycyclo-alkyl-arylgroup means a fused ring polycyclic group that includes at least onearyl ring and at least one cycloalkyl ring that are fused together toform a fused ring structure. For purposes of non-limiting illustration,examples of fused ring polycyclic-aryl-alkyl groups include, but are notlimited to, indenyl, 9H-flourenyl, cyclopentanaphthenyl, and indacenyl.

The term “aralkyl” as used herein, and in accordance with someembodiments, includes but is not limited to C₆-C₂₄ aralkyl, such as butnot limited to C₆-C₁₀ aralkyl, and means an aryl group substituted withan alkyl group. Examples of aralkyl groups include, but are not limitedto, those recited previously herein.

Suitable untreated fillers for use in the process of the presentinvention can include a wide variety of materials known to one havingordinary skill in the art. Non-limiting examples can include inorganicoxides such as inorganic particulate and amorphous solid materials whichpossess either oxygen (chemisorbed or covalently bonded) or hydroxyl(bound or free) at an exposed surface, such as but not limited to oxidesof the metals in Periods 2, 3, 4, 5 and 6 of Groups Ib, IIb, IIIa, IIIb,IVa, IVb (except carbon), Va, VIa, VIIa and VIII of the Periodic Tableof the Elements in Advanced Inorganic Chemistry: A Comprehensive Text byF. Albert Cotton et al, Fourth Edition, John Wiley and Sons, 1980.Non-limiting examples of suitable inorganic oxides can include but arenot limited to aluminum silicates, silica such as silica gel, colloidalsilica, precipitated silica, and mixtures thereof.

The inorganic oxide can be silica with some embodiments. For example, incertain embodiments, the inorganic oxide can include precipitatedsilica, colloidal silica, and mixtures thereof. The silica can have anaverage ultimate particle size of less than 0.1 micron, or greater than0.001 micron, or from 0.01 to 0.05 micron, or from 0.015 to 0.02 micron,as measured by electron microscope. Further, the silica can have asurface area of from 25 to 1000 square meters per gram, such as from 75to 250 square meters per gram, or from 100 to 200 square meters pergram, as determined by the Brunauer, Emmett, and Teller (BET) method inaccordance with ASTM D1993-91. With some embodiments, the filler isprecipitated silica.

As previously mentioned, the untreated filler slurry is treated with atreating composition that can include a treating agent. In certainembodiments, the treating agent can act as a coupling agent. The term“coupling agent” as used herein means a material that binds (ionicallyor covalently) to (i) groups present on the surface of the fillerparticle (such as on the silica surface), as well as to (ii) functionalgroups present on the component(s) of the polymeric matrix into whichthe filler is incorporated. Thus, the filler particles can be “coupled”to the components in the polymeric matrix.

Alternatively, with some embodiments, the treating agent can act as anon-coupling agent. The term “non-coupling agent” as used herein means amaterial that serves to compatibilize the treated filler with thepolymeric composition in which the treated filler ultimately is used.That is, the non-coupling agent can affect the free surface energy ofthe treated filler particles to make the treated filler particles have asurface energy similar to that of the polymeric composition. Thisfacilitates incorporation of the treated filler into the polymericcomposition, and can serve to improve (such as, decrease) mix viscosityof the composition. It should be noted that non-coupling agents are notexpected to couple with the rubber matrix beyond Van der Waalinteractions. As used herein, the term “non-coupling agent” can be usedinterchangeably with “compatibilizer”.

It should be noted that many of the treatment agents may simultaneouslyfunction as both a coupling agent and a non-couplingagent/compatibilizer.

The treating agent, with some embodiments of the present invention, caninclude a polymer. Non-limiting examples of suitable polymers include,but are not limited to, acrylic polymers, styrene butadiene latexes,natural rubber latexes, and combinations thereof.

With some embodiments, the acrylic polymer can be selected from acrylichomopolymers and/or acrylic copolymers, and can have a polymerarchitecture including, but not limited to, a random copolymerarchitecture, a comb polymer architecture, a block copolymerarchitecture, and a hyperbranched polymer architecture. The backbone andeach tooth of an acrylic comb polymer can each independently have apolymer chain architecture selected from random copolymer chainarchitecture, block copolymer chain architecture, and homopolymer chainarchitecture, with some embodiments of the present invention. Thus, theacrylic polymer can include, but is not limited to, acrylic randomcopolymers, acrylic comb polymers, acrylic block copolymers,hyperbranched acrylic polymers, and combinations thereof.

Acrylic comb polymers and acrylic block copolymers that are used withsome embodiments of the present invention can each be independentlyprepared with art-recognized methods, such as living radicalpolymerization, such as atom transfer radical polymerization. Acrylicrandom copolymers and acrylic homopolymers used with some embodiments ofthe present invention can be prepared by art-recognized methods, such asliving radical polymerization and free radical polymerization.

Further, as used herein, the term “hyperbranched acrylic polymer” refersto an acrylic polymer having a main polymer chain and at least twobranching points along the main polymer chain. In certain embodiments,the hyperbranched acrylic polymer includes ethylenic unsaturation. Asused herein, the term “ethylenic unsaturation” refers collectively toaliphatic carbon-carbon double bonds and aliphatic carbon-carbon triplebonds. Methods and materials for preparing the hyperbranched acrylicpolymer are disclosed in U.S. patent application Ser. No. 13/834,804 atparagraphs [0015] to [0024], which disclosure is incorporated byreference herein.

In certain embodiments, the hyperbranched acrylic polymers used as atreating agent exhibit an alpha parameter derived from the Mark-Houwinkequation of 0.2 to 0.7, and in some embodiments, the hyperbranchedacrylic polymers of the present invention exhibit an alpha parameterderived from the Mark-Houwink equation of 0.3 to 0.6.

The Mark-Houwink relationship between molar mass (M) and intrinsicviscosity (η) ([η]=K·Mα provides information about the structure of thepolymer. The alpha parameter indicates the degree of branching and canbe determined by multi detection size-exclusion chromatography asdescribed by Paillet et al., Journal of Polymer Science Part A: PolymerChemistry, 2012, 50, 2967-2979, which is incorporated by referenceherein.

The hyperbranched acrylic polymer produced in accordance with someembodiments of the present invention can have a weight average molecularweight (Mw) between 10,000 and 200,000, such as between 15,000 and150,000, and, in certain embodiments, between 20,000 and 100,000 gramsper mole. Further, in certain embodiments, the hyperbranched acrylicpolymers of the present invention are water-dispersible. As used herein,the term “water-dispersible” means that a material may be dispersed inwater without the aid or use of a surfactant, such as but not limited toa surfactant monomer. As used herein, the term “surfactant monomers”refers to monomers that when added to water reduces the surface tensionof water. As such, in certain embodiments, the hyperbranched acrylicpolymers used in the practice of the invention can be substantiallyfree, can be essentially free, and can be completely free of surfactantmonomers. The term “substantially free” as used in this context meansthe hyperbranched acrylic polymers contain less than 1000 parts permillion (ppm), “essentially free” means less than 100 ppm, and“completely free” means less than 20 parts per billion (ppb) of asurfactant monomer.

In certain embodiments, the hyperbranched acrylic polymer is dispersedwith at least one ethylenically unsaturated monomer and polymerized toat least encapsulate the untreated filler, such as in a microgel. Asused herein, the term “microgel” refers to internally crosslinkedmicro-sized polymer and the term “partially encapsulate” refers totreated fillers that are at least partially confined or enclosed withina microgel. Suitable polymerization techniques for forming the microgelare disclosed in U.S. patent application Ser. No. 13/834,804 atparagraphs [0050] to [0052] and the Examples section, all of which areincorporated by reference herein.

Further, the ethylenically unsaturated monomers can be monoethylenicallyunsaturated monomers, polyethylenically unsaturated monomers, ormixtures thereof. In certain embodiments, the ethylenically unsaturatedmonomers are hydrophobic ethylenically unsaturated monomers. As usedherein, “hydrophobic monomers” refer to monomers that do not have anaffinity for water and do not to dissolve in, mix with, or swell in awater or aqueous medium. Non-limiting examples of monoethylenically andpolyethylenically unsaturated monomers used to prepare the microgels inaccordance with some embodiments of the present invention include, butare not limited to, any of the hydrophobic monoethylenically andpolyethylenically unsaturated monomers previously discussed. Forexample, suitable ethylenically unsaturated monomers include, but arenot limited to, methyl methacrylate, n-butyl acrylate, isobutylacrylate, tert-butyl acrylate, and ethyleneglycol dimethacrylate.

As previously mentioned, the treating agent can, with some embodiments,include styrene butadiene latexes and/or natural rubber latexes.“Styrene butadiene latexes” refer to stable dispersions of styrenebutadiene polymers. Further, as used herein, a “natural rubber latex”refers to a stable dispersion of a rubber which includes, as a mainbackbone, polyisoprene obtained from sap produced by plant species suchas, but not limited to, Hevea brasiliensis, Parthenoim argentatum,and/or Sapotaceae. In certain embodiments, the natural rubber latexincludes cis-1,4-polyisoprene.

With some embodiments of the present invention, the treating agent caninclude a polymer (such as any of the polymers previously described)having at least one first group that interacts with the untreated fillerand at least one second group that interacts with a rubber matrix intowhich the treated filler is incorporated. As used herein, the term“interacts” means that the at least one first group and the at least onesecond group binds ionically and/or covalently to the untreated fillerand rubber matrix, respectively. With some embodiments, the at least onefirst group interacts with the untreated filler by binding ionicallyand/or covalently to the surface of the untreated filler. With someother embodiments, the at least one second group interacts with a rubbermatrix by binding covalently with at least a portion of the matrix.

The at least one first group includes, with some embodiments, esters,carboxylic acids, imides including cyclic imides, anhydrides includingcyclic anhydrides, diacids, lactones, oxiranes, isocyanates,alkoxysilanes, and/or derivatives thereof. As used herein, the term“derivatives thereof” refers to salts and hydrolysis products of suchgroups.

The at least one second group can be the same or different from the atleast one first group. With some embodiments, the at least one secondgroup includes formyl, keto, thiol, sulfido, halo, amino, alkenyl,alkynyl, alkyl such as a C₃-C₃₆ alkyl, and/or derivatives thereof. Ketogroups from which the second group can be selected can be represented bythe formula —C(O)(R′), where R′ is a hydrocarbyl group, which can beselected from those classes and examples of hydrocarbyl groups describedpreviously herein. With some other embodiments, the at least one secondgroup includes hydroxyl, anhydrides including cyclic anhydrides,oxiranes, and/or derivatives thereof.

With some embodiments, the treating agent can include a polymer (such asany of the polymers previously described) having at least one firstgroup and/or at least one second group selected from an anhydride and/orderivatives thereof. Non-limiting examples of suitable anhydrides andderivatives thereof include, but are not limited to, maleic anhydride,maleimide, and combinations thereof. Such anhydride functional polymersinclude residues of maleic anhydride and/or derivatives thereof, whichcan be referred to as maleated polymers. Suitable maleated polymers andlatexes thereof are commercially available from Westlake Chemical underthe trade name EPOLENE®.

With some embodiments, the anhydride functional polymers and/orderivatives thereof can be prepared from a maleimide monomer representedby the following formula (A):

where R* is hydrogen, or C₁ to C₁₀ hydrocarbyls.

With some other embodiments, the anhydride functional polymer and/orderivative thereof is prepared from maleic anhydride, and, afterformation thereof, at least some of the maleic anhydride residues in thepolymer are converted to maleimide groups by reaction with an aminefollowed by dehydration in accordance with art-recognized methods.

As previously described, the treating agent can include a styrenebutadiene latex having at least one first group and at least one secondgroup. With some of these embodiments, the at least one first group isselected from a carboxylic acid and/or a derivative thereof. Suitablecarboxylated styrene butadiene latexes include, but are not limited to,those commercially available from Kraton Performance Polymers, Inc. andOMNOVA Solutions Inc.

With some embodiments, in addition to the treatment agents listed above,the treating composition can further include a first or additionalcoupling agent that is different than the treating agent. In certainembodiments, the coupling agent can include any of a variety oforganosilanes. Examples of suitable organosilanes that can be used withsome embodiments of the present invention include those represented byFormula (I):

(R₁)_(a)(R₂)_(b)SiX_(4-a-b)  (I).

With reference to Formula (I), R₁ is independently for each “a” ahydrocarbyl group having 1 to 36 carbon atoms and a functional group.The functional group of the hydrocarbyl group is vinyl, allyl, hexenyl,epoxy (oxirane), glycidoxy, (meth)acryloxy, sulfide, isocyanato (—NCO),polysulfide, mercapto, or halogen. With reference to Formula (I), R₂ isindependently for each “b” a hydrocarbyl group having from 1 to 36carbon atoms or hydrogen. X of Formula (I) is independently halogen oralkoxy having 1 to 36 carbon atoms; subscript “a” is 0, 1, 2, or 3;subscript “b” is 0, 1, or 2; (a+b) is 1, 2, or 3. With some embodiments,there is the proviso that when b is 1, (a+b) is 2 or 3. With somefurther embodiments of the present invention, the treating compositionfurther includes a coupling agent represented by Formula (I), in which Xis alkoxy; a is 1; b is 0; and the functional group of the hydrocarbylof R₁ is halogen.

Examples of halo-functional organosilanes, such as those represented byFormula (I), include, but are not limited to, (4-chloromethyl-phenyl)trimethoxysilane, (4-chloromethyl-phenyl) triethoxysilane,[2-(4-chloromethyl-phenyl)-ethyl] trimethoxysilane,[2-(4-chloromethyl-phenyl)-ethyl] triethoxysilane,(3-chloro-propenyl)-trimethoxysilane,(3-chloro-propenyl)-triethoxysilane, (3-chloro-propyl)-triethoxysilane,(3-chloro-propyl)-trimethoxysilane, trimethoxy-(2-p-tolyl-ethyl)silaneand/or triethoxy-(2-p-tolyl-ethyl)silane.

In certain embodiments, the additional coupling agent can be present inthe slurry in an amount ranging from 0.25 to 30.0 weight percent, suchas 1 to 15 weight percent, or 5 to 10 weight percent based on the totalmass of SiO₂ which has been precipitated.

In certain embodiments, the treating composition useful in the processof the present invention also can further include a sulfur-containingorganosilane that is different from the aforementioned optionalorganosilane coupling agents, such as represented by Formula (I).Non-limiting examples of such materials can include, but are not limitedto, organosilanes represented by the following Formula (II):

(R₃)_(c)(R₄)_(d)SiY_(4-c-d)  (II).

With reference to Formula (II), R₃ independently for each “c” can be ahydrocarbyl group having 1 to 12 carbon atoms and a functional group.The functional group can be sulfide, polysulfide or mercapto. Withreference to Formula (II), R₄ independently for each “d” can be ahydrocarbyl group having from 1 to 18 carbon atoms or hydrogen. Each Yeach can independently be halogen or an alkoxy group having 1 to 12carbon atoms. Subscript “c” can be 0, 1, 2, or 3; subscript “b” can be0, 1, or 2; and c+d can be 1, 2, or 3. With some embodiments, there isthe proviso that when b is 1 then a+b is 2 or 3. The R₃ and R₄ groups ofFormula (II) can be selected such that they can react with the polymericcomposition in which the treated filler can be incorporated.

Additionally, the sulfur-containing organosilane can includebis(alkoxysilylalkyl)polysulfides represented by following Formula(III):

Z′-alk-S_(n′)-alk-Z′  (III).

With reference to Formula (III), “alk” represents a divalent hydrocarbonradical having from 1 to 18 carbon atoms; n′ is an integer from 2 to 12;and Z′ is:

in which R₅ is independently an alkyl group having from 1 to 4 carbonatoms or phenyl, and each R₆ is independently an alkoxy group havingfrom 1 to 8 carbon atoms, a cycloalkoxy group with from 5 to 8 carbonatoms, or a straight or branched chain alkylmercapto group with from 1to 8 carbon atoms. The R₅ and R₆ groups can be the same or different.Also, the divalent alk group can be straight or branched chain, asaturated or unsaturated aliphatic hydrocarbon group or a cyclichydrocarbon group. Non-limiting examples ofbis(alkoxysilylalkyl)-polysulfides can includebis(2-trialkoxysilylethyl)-polysulfides in which the trialkoxy group canbe trimethoxy, triethoxy, tri(methylethoxy), tripropoxy, tributoxy,etc., up to trioctyloxy, and the polysulfide can be either di-, tri-,tetra-, penta-, or hexasulfide, or mixtures thereof. Furthernon-limiting examples can include the correspondingbis(3-trialkoxysilylpropyl)-, bis(3-trialkoxysilylisobutyl),-bis(4-trialkoxysilylbutyl)-, etc., up tobis(6-trialkoxysilyl-hexyl)-polysulfides. Further non-limiting examplesof bis(alkoxysilylalkyl)-polysulfides are described in U.S. Pat. No.3,873,489, at column 6, lines 5-55, and in U.S. Pat. No. 5,580,919, atcolumn 11, lines 11-41. Further non-limiting examples of such compoundscan include: 3,3′bis(trimethoxysilylpropyl)disulfide,3,3′-bis(triethoxysilylpropyl)tetrasulfide,

3,3′-bis(trimethoxysilylpropyl)tetrasulfide,2,2′-bis(triethoxysilylethyl)tetrasulfide,

3,3′-bis(trimethoxysilylpropyl)trisulfide,3,3′-bis(triethoxysilylpropyl)tri sulfide,

3,3′-bis(tributoxysilylpropyl)disulfide,3,3′-bis(trimethoxysilylpropyl)hexasulfide, and

3,3′-bis(trioctoxysilylpropyl)tetrasulfide and mixtures thereof.

The sulfur-containing organosilane also can be a mercaptoorganometalliccompound represented by the following Formula (IV):

With reference to Formula (IV), M′ is silicon, L is halogen or —OR₈, Qis hydrogen, C₁-C₁₂ alkyl, or halo-substituted C₁-C₁₂ alkyl, R₇ isC₁-C₁₂ alkylene, R₈ is C₁-C₁₂ alkyl or alkoxyalkyl containing from 2 to12 carbon atoms, the halogen or (halo) groups being chloro, bromo, iodoor fluoro, and n is 1, 2 or 3. In a non-limiting embodiment,mercaptoorganometallic reactants having two mercapto groups can be used.

Non-limiting examples of useful mercaptoorganometallic compounds includebut are not limited to mercaptomethyltrimethoxysilane,mercaptoethyltrimethoxysilane, mercaptopropyltrimethoxysilane,mercaptomethyltriethoxysilane, mercaptoethyltripropoxysilane,mercaptopropyltriethoxysilane, (mercaptomethyl)dimethylethoxysilane,(mercaptomethyl)methyl diethoxysilane,3-mercaptopropyl-methyldimethoxysilane, and mixtures thereof.

With some embodiments of the present invention, the sulfur-containingorganosilane can be a mercaptoorganometallic compound such as amercaptosilane different from the organosilane used in the treatingcomposition of step (a), for example, mercaptopropyltrimethoxysilaneand/or mercaptomethyltriethoxysilane.

Also, it is contemplated that the sulfur-containing organosilanerepresented by Formula (IV), which is different from the aforementionedorganosilane coupling agent represented by Formula (I), that can be usedin step (a) of the process of the present invention, can be amercaptoorganometallic compound in which the mercapto group is blocked,i.e., the mercapto hydrogen atom is replaced by another group. Blockedmercaptoorganometallic compounds can have an unsaturated heteroatom orcarbon bound directly to sulfur via a single bond. Non-limiting examplesof specific blocking groups can include thiocarboxylate ester,dithiocarbamate ester, thiosulfonate ester, thiosulfate ester,thiophosphate ester, thiophosphonate ester, and thiophosphinate ester.

With some non-limiting embodiments, in which a blockedmercaptoorganometallic compound is used as an optional couplingmaterial, a deblocking agent can be added to the polymeric compoundmixture to deblock the blocked mercaptoorganometallic compound. Withsome non-limiting embodiments in which water and/or alcohol are presentin the mixture, a catalyst, such as tertiary amines, Lewis acids orthiols, can be used to initiate and promote the loss of the blockinggroup by hydrolysis or alcoholysis to liberate the correspondingmercaptoorganometallic compounds. Non-limiting examples of blockedmercaptosilanes can include but are not limited to2-triethoxysilyl-1-ethyl thioacetate, 3-trimethoxy-silyl-1-propylthiooctoate, bis-(3-triethoxysilyl-1-propyl)-methyldithiophosphonate,3-triethoxysilyl-1-propyldimethylthiophosphinate,3-triethoxysilyl-1-propylmethylthiosulfate,3-triethoxysilyl-1-propyltoluenethiosulfonate, and mixtures thereof.

The amount of these optional sulfur-containing organosilanes can varywidely and can depend upon the particular material selected. Forexample, the amount of these optional sulfur-containing organosilanescan be greater than 0.1% based on the weight of untreated filler, suchas from 0.5% to 25% based on the weight of untreated filler, or from 1%to 20%, or from 2% to 15%.

In certain embodiments, the treating composition can further include ahalo-functional organosilane, which includes a monomeric, dimeric,oligomeric and/or or polymeric compound possessing halogen functionalityand alkanedioxysilyl functionality derived from (i)polyhydroxyl-containing compounds in which the alkanedioxy group iscovalently bonded to a single Si atom through Si—O bonds to form a ring;and/or (ii) the alkanedioxy groups are covalently bonded to at least twoSi atoms through Si—O bonds to form a dimer, oligomer, or polymer inwhich adjacent silyl units are bonded to each other through bridgedalkanealkoxy structures. Such halo-functional organosilanes aredescribed in detail in United States Published Patent Application No.2011/0003922A1, published Jan. 6, 2011, at paragraphs [0020] to [0057],the cited portions of which are incorporated by reference herein.

Mixtures of any of the aforementioned coupling agents can be used in theprocess of the present invention.

With some embodiments, in addition to the treating agent describedpreviously herein, the treating composition can optionally furtherinclude a first or additional non-coupling agent/compatibilizer that isdifferent from the treating agent. The additional non-couplingagent/compatibilizer can be selected from saturated biopolymers,saturated fatty acids, saturated organic acids, saturated polymeremulsions, saturated polymer coating composition, and mixtures thereof.The additional non-coupling agent/compatibilizer can alternatively orfurther include a surfactant selected from anionic, nonionic andamphoteric surfactants, and mixtures thereof.

The additional non-coupling agent/compatibilizer can, with someembodiments, be present in an amount of from greater than 1% to 25% byweight based on the total weight of untreated filler, such as the totalmass of SiO₂ which has been precipitated. For example, the additionalnon-coupling agent/compatibilizer can be chosen from salts of fattyacids, alkyl sarcosinates, salts of alkyl sarcosinates, and mixturesthereof. Specific non-limiting examples of such can be found in U.S.Pat. No. 7,569,107 at column 5, line 9, to column 7, line 21, the citedportions of which are incorporated by reference herein. With someembodiments of the present invention, the additional non-couplingagent/compatibilizer can include one or more anionic surfactantsselected from sodium stearate, ammonium stearate, ammonium cocoate,sodium laurate, sodium cocyl sarcosinate, sodium lauroyl sarconsinate,sodium soap of tallow, sodium soap of coconut, sodium myristoylsarcosinate, and/or stearoyl sarcosine acid.

The additional non-coupling agent/compatibilizer, with some embodiments,is present in an amount of from greater than 1% up to and including 25%by weight, for example 2.0% to 20.0%, or 4% to 15%, or 5% to 12% byweight based on the total weight of the untreated filler, such as thetotal mass of SiO₂ that has been precipitated.

With some embodiments, the additional non-coupling agent/compatibilizercan be a non-coupling organosilane. Non-limiting examples ofnon-coupling silanes from which the additional non-couplingagent/compatibilizer can be selected, with some embodiments, includeoctadecyltriethoxysilane, octadecyltrichlorosilane,octadecyltrimethoxysilane, propyltriethoxysilane,propyltrimethoxysilane, propyltrichlorosilane, n-octyltrimethoxysilane,n-octyltriethoxysilane, n-octyltrichlorosilane, n-hexyltrimethoxysilane,n-hexyltriethoxysilane, and/or n-hexyltrichlorosilane.

It should be understood that, for purposes of the present invention, anyof the aforementioned organosilanes, including the organosilane havingthe structure (I) as described above, can, with some embodiments,include partial hydrolyzates thereof.

The untreated filler used with various embodiments of the presentinvention can be prepared using any of a variety of art-recognizedmethods. For example, in the instance where the untreated filler isuntreated silica, the untreated filler can prepared by combining anaqueous solution of soluble metal silicate with acid solution to form asilica slurry; the silica slurry optionally can be aged; acid or basecan be added to the optionally aged silica slurry to adjust pH of theslurry; the silica slurry can be filtered, optionally washed, and thendried using art-recognized techniques. A treatment composition, such asany of those described above, can be added at any step in theabove-described process prior to drying in accordance with variousembodiments of the present invention.

With some alternative embodiments, the present invention is directed toa process for producing a treated precipitated silica that includes:

(a) combining alkali metal silicate and acid to form an untreatedslurry;

(b) optionally, treating the untreated slurry with the treatingcomposition including the treating agent to form a treated slurry;

(c) drying the untreated slurry of (a), or drying the treated slurry of(b), to in each case produce dried precipitated silica;

(d) forming an aqueous slurry of the dried precipitated silica of step(c) with the treatment composition that includes the treating agent toform a treated silica slurry; and

(e) drying the treated silica slurry to produce a dried treatedprecipitated silica.

With some embodiments and with reference to the above-summarizedprocess, whether or not a treatment composition has been included in theuntreated slurry prior to drying, an aqueous slurry of the driedprecipitated silica (treated or untreated) can be prepared, and atreatment composition can then be added to form a treated slurry ofprecipitated silica, which is subsequently re-dried to produce a treatedprecipitated silica.

Additionally, the precipitated silica of any of the foregoingembodiments can be included in a polymer blend and compounded with atreatment composition as described previously herein.

Further detailed descriptions of the process for forming the treatedsilica can be found herein below in the Examples.

Suitable metal silicates that can be used with some embodiments of thepresent invention can include a wide variety of materials known in theart. Non-limiting examples can include, but are not limited to, aluminasilicate, lithium silicate, sodium silicate, potassium silicate, andmixtures thereof. The metal silicate can be represented by the followingstructural formula:

M₂O(SiO2)x

wherein M can be alumina, lithium, sodium or, potassium, and x can rangefrom 0.1 to 4.

Suitable acids that can be used with some embodiments of the presentinvention can be selected from a wide variety of acids known in the art.Non-limiting examples can include, but are not limited to, mineralacids, organic acids, carbon dioxide, sulfuric acid, and mixturesthereof.

The treated fillers which are prepared by the processes of the presentinvention are suitable for inclusion in organic polymeric compositions.The treated filler materials prepared by the process of the presentinvention are useful with some embodiments in rubber compoundingcompositions, such as rubber compositions used in the manufacture oftires and tire components such as tire treads.

Polymeric compositions into which treated fillers prepared accordingwith the method of the present invention include, but are not limitedto, those described in Kirk Othmer Encyclopedia of Chemical Technology,Fourth Edition, 1996, Volume 19, pp 881-904, which description is hereinincorporated by reference. The treated filler prepared in accordancewith various embodiments of the present invention can be admixed withthe polymer or the polymerizable components thereof while the physicalform of the polymer or polymerizable components is in any liquid orcompoundable form such as a solution, suspension, latex, dispersion, andthe like. The polymeric compositions containing the treated filler ofthe present invention can be milled, mixed, molded and, optionally,cured, by any manner known in the art, to form a polymeric article.Classes of polymers can include, but are not limited to, thermoplasticand thermosetting resins, rubber compounds and other polymers havingelastomeric properties.

The aforementioned polymers can include, for example, alkyd resins,oil-modified alkyd resins, unsaturated polyesters, natural oils (e.g.,linseed, tung, soybean), epoxides, nylons, thermoplastic polyester(e.g., polyethyleneterephthalate, polybutyleneterephthalate),polycarbonates, i.e., thermoplastic and thermoset, polyethylenes,polybutylenes, polystyrenes, polypropylenes, ethylene propylene co- andterpolymers, acrylics (homopolymer and copolymers of acrylic acid,acrylates, methacrylates, acrylamides, their salts, hydrohalides, etc.),phenolic resins, polyoxymethylene (homopolymers and copolymers),polyurethanes, polysulfones, polysulfide rubbers, nitrocelluloses, vinylbutyrates, vinyls (vinyl chloride and/or vinyl acetate containingpolymers), ethyl cellulose, the cellulose acetates and butyrates,viscose rayon, shellac, waxes, ethylene copolymers (e.g., ethylene-vinylacetate copolymers, ethylene-acrylic acid copolymers, ethyleneacrylatecopolymers), organic rubbers (both synthetic and natural rubbers), andthe like.

The amount of treated filler that can be used in a polymeric compositioncan vary widely depending upon the polymeric composition and the desiredproperties of the article to be formed from the polymeric composition.For example, the amount of treated filler present in the polymericcomposition can range from 5 up to 70 weight %, based on the totalweight of the polymeric composition.

With some non-limiting embodiments, the polymeric composition caninclude an organic rubber. Non-limiting examples of such rubbers caninclude but are not limited to natural rubber; those formed from thehomopolymerization of butadiene and its homologues and derivatives, suchas cis-1,4-polyisoprene; 3,4-polyisoprene; cis-1,4-polybutadiene;trans-1,4-polybutadiene; 1,2-polybutadiene; and those formed from thecopolymerization of butadiene and its homologues and derivatives withone or more copolymerizable monomers containing ethylenic unsaturation,such as styrene and its derivatives, vinyl-pyridine and its derivatives,acrylonitrile, isobutylene and alkyl-substituted acrylates, such asmethyl methacrylate. Further non-limiting examples can includestyrene-butadiene copolymer rubber composed of various percentages ofstyrene and butadiene and employing the various isomers of butadiene asdesired (hereinafter “SBR”); terpolymers of styrene, isoprene andbutadiene polymers, and their various isomers; acrylonitrile-basedcopolymer and terpolymer rubber compositions; and isobutylene-basedrubber compositions; or a mixture thereof, as described in, for example,U.S. Pat. Nos. 4,530,959; 4,616,065; 4,748,199; 4,866,131; 4,894,420;4,925,894; 5,082,901; and 5,162,409.

Non-limiting examples of suitable organic polymers can includecopolymers of ethylene with other high alpha olefins, such as propylene,butene-1 and pentene-1 and a diene monomer. The organic polymers can beblock, random, or sequential and can be prepared by methods known in theart, such as but not limited to emulsion (e.g. e-SBR) or solutionpolymerization processes (e.g., s-SBR). Further non-limiting examples ofpolymers for use in the present invention can include those which arepartially or fully functionalized including coupled or star-branchedpolymers. Additional non-limiting examples of functionalized organicrubbers can include polychloroprene, chlorobutyl and bromobutyl rubber,as well as brominated isobutylene-co-paramethylstyrene rubber. In anon-limiting embodiment, the organic rubber can be polybutadiene, s-SBR,and mixtures thereof.

The polymeric composition can be a curable rubber. The term “curablerubber” is intended to include natural rubber and its various raw andreclaimed forms as well as various synthetic rubbers. In alternatenon-limiting embodiments, curable rubber can include combinations of SBRand butadiene rubber (BR), SBR, BR and natural rubber and any othercombinations of materials previously disclosed as organic rubbers. Inthe description of this invention, the terms “rubber”, “elastomer” and“rubbery elastomer” can be used interchangeably, unless indicatedotherwise. The terms “rubber composition”, “compounded rubber” and“rubber compound” are used interchangeably to refer to rubber which hasbeen blended or mixed with various ingredients and materials, and suchterms are well-known to those having skill in the rubber mixing orrubber compounding art.

Rubber compositions that include the treated filler produced by theprocess of the present invention and can be used in the manufacture of amyriad of rubber articles, such as for example, a tire at least onecomponent of which, e.g., the tread, comprises the cured rubbercomposition, as well as other rubber articles such as shoe soles, hoses,seals, cable jackets, gaskets, belts, and the like. Rubber compositionscomprising the treated filler produced by the process of the presentinvention are particularly advantageous for use in the manufacture oftire treads exhibiting low rolling resistance and high wear resistance,including when the tire treads are based on natural rubber. Moreover,with some embodiments, lower cure temperatures can be achieved for suchnatural rubber compositions containing the treated filler produced bythe process of the present invention.

The treated filler of the present invention (as a powder, granule,pellet, slurry, aqueous suspension, or solvent suspension) may becombined with base material, i.e., material used in the product to bemanufactured, to form a mixture referred to as a master batch. In themaster batch, the treated filler may be present in higher concentrationthan in the final product. Aliquots of this mixture are typically addedto production-size quantities during mixing operations in order to aidin uniformly dispersing very small amounts of such additives topolymeric compositions, e.g., plastics, rubbers and coatingcompositions.

The treated filler may be combined with emulsion and/or solutionpolymers, e.g., organic rubber comprising solution styrene/butadiene(SBR), polybutadiene rubber, or a mixture thereof, to form a masterbatch. One contemplated embodiment is a master batch comprising acombination of organic rubber, water-immiscible solvent, treated fillerand, optionally, processing oil. Such a product may be supplied by arubber producer to a tire manufacturer. The benefit to the tiremanufacturer of using a master batch is that the treated filler isuniformly dispersed in the rubber, which results in minimizing themixing time to produce the compounded rubber. The master batch cancontain from 10 to 150 parts of treated silica per 100 parts of rubber(phr), or from 20 to 130 phr, or from 30 to 100 phr, or from 50 to 80phr.

The present invention is more particularly described in the followingexamples, which are intended to be illustrative only, since numerousmodifications and variations therein will be apparent to those skilledin the art. Unless otherwise specified, all parts and all percentagesare by weight.

EXAMPLES Part 1—Analytical Testing

The silica CTAB surface area values reported in the examples of thisapplication were determined using a CTAB solution and the hereinafterdescribed method. The analysis was performed using a Metrohm 751 Titrinoautomatic titrator, equipped with a Metrohm Interchangeable “Snap-In” 50milliliter burette and a Brinkmann Probe Colorimeter Model PC 910equipped with a 550 nm filter. In addition, a Mettler Toledo HB43 orequivalent was used to determine the 105° C. moisture loss of the silicaand a Fisher Scientific Centrific™ Centrifuge Model 225 was used forseparating the silica and the residual CTAB solution. The excess CTABwas determined by auto titration with a solution of AEROSOL® OT(dioctylsodium sulfosuccinate, available from Cytec Industries, Inc.)until maximum turbidity was attained, which was detected with the probecolorimeter. The maximum turbidity point was taken as corresponding to amillivolt reading of 150. Knowing the quantity of CTAB adsorbed for agiven weight of silica and the space occupied by the CTAB molecule, theexternal specific surface area of the silica was calculated and reportedas square meters per gram on a dry-weight basis.

Solutions required for testing and preparation included a buffer of pH9.6, cetyl [hexadecyl] trimethyl ammonium bromide (CTAB, also known ashexadecyl trimethyl ammonium bromide, technical grade), AEROSOL® OT and1N sodium hydroxide. The buffer solution of pH 9.6 was prepared bydissolving 3.101 g of orthoboric acid (99%; technical grade,crystalline) in a one-liter volumetric flask, containing 500 millilitersof deionized water and 3.708 grams of potassium chloride solids (FisherScientific, Inc., technical grade, crystalline). Using a burette, 36.85milliliters of the 1N sodium hydroxide solution was added. The solutionwas mixed and diluted to volume.

The CTAB solution was prepared using 11.0 g+/−0.005 g of powdered CTABonto a weighing dish. The CTAB powder was transferred to a 2-literbeaker and the weighing dish was rinsed with deionized water.Approximately 700 milliliters of the pH 9.6 buffer solution and 1000milliliters of distilled or deionized water was added to the 2-literbeaker and stirred with a magnetic stir bar. A large watch glass wasplaced on the beaker and the beaker was stirred at room temperatureuntil the CTAB powder was totally dissolved. The solution wastransferred to a 2-liter volumetric flask, rinsing the beaker and stirbar with deionized water. The bubbles were allowed to dissipate, and thesolution diluted to volume with deionized water. A large stir bar wasadded and the solution mixed on a magnetic stirrer for approximately 10hours. The CTAB solution can be used after 24 hours and for only 15days. The AEROSOL® OT solution was prepared using 3.46 g+/−0.005 g,which was placed onto a weighing dish. The AEROSOL® OT on the weighingdish was rinsed into a 2-liter beaker, which contained about 1500milliliter deionized water and a large stir bar. The AEROSOL® OTsolution was dissolved and rinsed into a 2-liter volumetric flask. Thesolution was diluted to the 2-liter volume mark in the volumetric flask.The AEROSOL® OT solution was allowed to age for a minimum of 12 daysprior to use. The shelf life of the AEROSOL® OT solution is 2 monthsfrom the preparation date.

Prior to surface area sample preparation, the pH of the CTAB solutionwas verified and adjusted to a pH of 9.6+/−0.1 using 1N sodium hydroxidesolution. For test calculations, a blank sample was prepared andanalyzed. 5 milliliters of the CTAB solution was pipetted and 55milliliters deionized water was added into a 150-milliliter beaker andanalyzed on a Metrohm 751 Titrino automatic titrator. The automatictitrator was programmed for determination of the blank and the sampleswith the following parameters: Measuring point density=2, Signaldrift=20, Equilibrium time=20 seconds, Start volume=0 ml, Stop volume=35ml, and Fixed endpoint=150 mV. The burette tip and the colorimeter probewere placed just below the surface of the solution, positioned such thatthe tip and the photo probe path length were completely submerged. Boththe tip and photo probe were essentially equidistant from the bottom ofthe beaker and not touching one another. With minimum stirring (settingof 1 on the Metrohm 728 stirrer) the colorimeter was set to 100% T priorto every blank and sample determination and titration was initiated withthe AEROSOL® OT solution. The end point was recorded as the volume (ml)of titrant at 150 mV.

For test sample preparation, approximately 0.30 grams of powdered silicawas weighed into a 50-milliliter container containing a stir bar.Granulated silica samples were riffled (prior to grinding and weighing)to obtain a representative sub-sample. A coffee mill style grinder wasused to grind granulated materials. Then 30 milliliters of the pHadjusted CTAB solution was pipetted into the sample container containingthe 0.30 grams of powdered silica. The silica and CTAB solution was thenmixed on a stirrer for 35 minutes. When mixing was completed, the silicaand CTAB solution were centrifuged for 20 minutes to separate the silicaand excess CTAB solution. When centrifuging was completed, the CTABsolution was pipetted into a clean container minus the separated solids,referred to as the “centrifugate”. For sample analysis, 50 millilitersof deionized water was placed into a 150-milliliter beaker containing astir bar. Then 10 milliliters of the sample centrifugate was pipettedfor analysis into the same beaker. The sample was analyzed using thesame technique and programmed procedure as used for the blank solution.

The BET surface area values reported in the examples of this applicationwere determined in accordance with the Brunauer-Emmet-Teller (BET)method in accordance with ASTM D1993-03. The BET surface area wasdetermined by fitting five relative-pressure points from a nitrogensorption isotherm measurement made with a Micromeritics TriStar 3000™instrument. A flow Prep-060™ station provided heat and a continuous gasflow to prepare samples for analysis. Prior to nitrogen sorption, thesilica samples were dried by heating to a temperature of 160° C. inflowing nitrogen (P5 grade) for at least one (1) hour.

The weight percent carbon (C) and sulfur (S) values reported in theexamples of this application were determined using a Flash 2000elemental analyzer. This system was set up to monitor carbon and sulfur.Typical parameters included: the combustion furnace being set to 950°C., the GC oven temperature being set to 65° C., the carrier helium gasflow rate being set to 140 mL/min, the reference helium gas flow ratebeing set to 100 mL/min, the oxygen flow rate being set to 250 mL/minand oxygen injection time of 5 seconds. For a given run, calibrationstandards, samples, and controls were typically run. To each 8-10 mg ofvanadium pentoxide (V₂O₅) was added. The sample size was between 2-4 mgand they were sealed in tin capsules prior to analysis. If the controlstandard was not within ±10% relative of the known accepted value or thesamples run in duplicate do not match (±5% relative), the entire samplerun was reanalyzed.

The weight percent mercaptan (SH) values reported in the examples ofthis application were determined using a back-titration method. Thesamples were dispersed in 75 mL of 2-Propanol, followed by addition ofexcess 0.1N Iodine solution. The test solution was then flushed withnitrogen, capped and allowed to stir for 15 minutes. The unreactediodine was subsequently back-titrated with standardized 0.05N sodiumthiosulfate to a colorless end point.

Part 2—Compound Testing Procedures and Equipment

Test Methods and Equipment Used Rubber Property Test Method EquipmentProcess ASTM D1646-00 Alpha Technologies Mooney MV2000 Viscometer CureASTM D2084-01 Monsanto MDR2000 Stress/Strain ASTM D412-98A Instron4204/4400R Density (water) ISO 2787-2008 Mettler Toledo XS203S withdensity kit Rebound ISO 4662 Zwick 5109 Hardness ASTM D2240-02, ZwickDigital Durometer Shore A Dynamic ASTM D5992-96, Ares-G2 RheometerProperties parallel plate geometry Filler ISO 11345, method B, OptigradeAB DisperGrader Dispersion 100X Magnification, 1000 NT+ Ref. Lib. G(CB/Silica) Abrasion ASTM D-5963-97A Hampden Model APH-40 Resistance DINAbrasion Tester

Example A

Precipitated silica slurry was produced through the sulfuric acidneutralization of a sodium silicate. This slurry was filtered and washedto produce a filter cake. This filter cake was mixed with a Cowles bladeto form a solid in liquid suspension. The percent solids of thisliquefied slurry was determined and used in Equation 1 along with thevalues shown for the respective treatment materials in Table 1 todetermine the amount of treatment applied for the respective examplesshown in Table 1.

Treatment (g)=Weight of slurry (g)*solids (wt. %/100)*maleinizedpolybutadiene (phs/100)*3-Mercaptopropyltriethoxysilane(phs/100)  Equation 1:

TABLE 1 Treatment Amount of 3-Mercaptopropyl- Amount of maleinizedtriethoxysilane Example polybutadiene*, phs (>95% Purity), phs CE-A.1(Comparative) 0 0 A.2 5 0 A.3 5 8 A.4 10 0 A.5 10 8 *Cray Valley'sRicobond ® 7004 (~30% actives in aqueous solution) phs = parts perhundred of solids

The respective treatment materials were added and mixed with a Cowlesblade for a minimum of 10 minutes. This treated slurry was than dried ina Niro spray drier (inlet temperature about 400° C.; outlet temperatureabout 105° C.). The moisture of the spray dried powders was in the 4-7weight percent range. The spray dried powders were granulated using anAlexanderwerk WP 120×40 Roller Compactor using a feed screw speed of54.5 rpm, a roll compactor speed of 4.6 rpm, a crusher speed of 55.0rpm, a screen gap of 1.5 mm, a vacuum pressure of 26.2 BAR and at agranulation pressure of 20 BAR. The physical and chemical properties areshown in Table 2. The higher carbon content for the treated silicas ofExamples A.2 thru A.5 confirms that the final products containmaleinized polybutadiene and that the amount increases with the amountadded. The higher SH and/or S for Examples A.3 and A.5 confirm thatthese respective final products also contain mercaptopropylsilane.

TABLE 2 Physical and Chemical Properties CTAB, BET, C, Example TreatmentDescription m²/g m²/g wt. % CE-A.1 None 178 184 <0.2 A.2 5 phsmaleinized polybutadiene 188 139 3.2 A.3 5 phs maleinizedpolybutadiene + 8 169 124 4.4 phs 3-Mercaptopropyltriethoxysilane A.4 10phs maleinized polybutadiene 195 118 6.3 A.5 10 phs maleinizedpolybutadiene + 8 166 117 7.0 phs 3-Mercaptopropyltriethoxysilane

Model Passenger Tread Formulation I

The model passenger tread formulations used to compare the inventiveExample A and comparative silicas is shown in Table 3. A 1.89 liter (L)Kobelco Stewart Bolling Inc. mixer (Model “00”) equipped with 4 wingrotors and a Farrel 12 inch two-roll rubber mill were used for mixingthe ingredients following ASTM D3182-89.

The formulations were mixed using one non-productive pass, allowing thecompound to cool, followed by a mill finish on a two-roll mill. For thefirst pass, the mixer speed was adjusted to 85 rpm and a startingtemperature of 150° F. Both the solution styrenebutadiene rubber (SBR),BUNA® VSL 5228-2 (vinyl content: 52%; styrene content: 28%; TreatedDistillate Aromatic Extract (TDAE) oil content: 37.5 parts per hundredrubber (phr); Mooney viscosity (ML(1+4)100° C.):50) obtainedcommercially from LANXESS, and butadiene rubber (BR), BUDENE™ 1207 (cis1,4 content 98%; Mooney viscosity (ML(1+4)100° C.):55) obtainedcommercially from The Goodyear Tire & Rubber Company, polymers wereadded to the mixer. After 30 seconds into the mix cycle half of the testsilica was added to the mixer. After another 30 seconds into the mixcycle the other half of the test silica as well as the VIVATEC® 500 TDAEprocessing oil obtained commercially from the H & R Group Inc. was addedto the mixer. After another 30 seconds into the mix cycle, the ram wasraised and the chute swept, i.e., the covering on the entry chute wasraised and any material that was found in the chute was swept back intothe mixer and the ram lowered. After another 30 seconds into the mixcycle the combination of KADOX®-720C surface treated zinc oxide,obtained commercially from Zinc Corporation of America, Rubber gradestearic acid, obtained commercially from R. E. Carroll, StangardSANTOFLEX® 13 antiozonant, described asN-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine, obtainedcommercially from Harwick Standard and SUNPROOF® Improved antiozonanthydrocarbon wax obtained commercially from Addivant™ USA, LLC was addedto the mixer. After another 30 seconds, the ram was raised and the chuteswept. From 150 seconds into the mix cycle forward the mixer speed wasadjusted to reach and/or maintain a temperature of 338° F.+/−5° F. forover a 390 second timeframe. The first pass was dropped at a temperatureof 338° F.+/−5° F. after approximately 540 seconds of total mix time.

Rubber Makers sulfur (“RM sulfur”), 100% active, obtained commerciallyfrom Taber, Inc., the SANTOCURE® CBS,n-cyclohexyl-2-benzothiazolesulfenamide obtained commercially fromHarwick Standard, and the diphenylguanidine (DPG), obtained commerciallyfrom Harwick Standard Inc., were blended into the cooled first passMasterbatch on a two-roll rubber mill. Milling was done forapproximately 5 minutes performing 5 side cuts and 5 end passes.

TABLE 3 Model Passenger Tread Formulation I Silica CE-A.1 to A.5 PASS 1Mix Program Step Additions Weight, grams POLYMERS VLS 5228-2 450.19 BR1207 109.16 SILICA ADDITION 1 Treated Silica 188.64 SILICA ADDITION 2Treated Silica 188.64 VIVATEC 500 21.83 OTHER Zinc Oxide 10.92 (720° C.)Stearic Acid 4.37 SANTOFLEX 13 8.73 SUNPROOF Improved 6.55 Subtotal wt:989.03 STOCK SHEETED OFF AT APPROXIMATELY .085″ STOCK COOLED BEFORE MILLFINISH AFTER A MINIMUM OF ONE HOUR REST MILL FINISH Additions Weight,grams Masterbatch 989.03 RM Sulfur 8.73 SANTOCURE CBS 13.10 DPG 2.18 18END PASSES Total wt: 1013.05

Stress/Strain test specimens were cured for 30″ at 150° C. while allother test specimens were cured for 40″ at 150° C. Specimen preparationand testing were performed using the procedures and equipment shown inpart 2. The compound performance properties are shown in Table 4.

TABLE 4 Model Passenger Tread Formulation Results Example CE-A.1A A.2AA.3A A.4A A.5A Silica component CE-A.1 A.2 A.3 A.4 A.5 Mooney Viscosity,ML(1 + 4) 136 130 153 91 93 Stress Strain 300/100% Modulus ratio 3.7 3.04.5 3.4 3.9 Toughness (Tensile * 8112 10483 5200 10349 8328 Elongation),MPa * % DIN Abrasion Loss, mm³ 185 165 161 158 147 ARES - TemperatureSweep, 1 Hz, 2% strain Tan (δ) @ 60° C. 0.113 0.137 0.131 0.192 0.132 @0° C. 0.273 0.305 0.406 0.393 0.393 Delta: 0° C.-60° C. 0.159 0.1670.275 0.201 0.261 ARES - Strain Sweep, 30° C., 1 Hz Δ G′, 0.5%-16% 7.58.4 2.9 5.1 3.0

A comparison of the treated silicas containing only the maleinizedpolybutadiene treatment (examples A.2A and A.4A) to the non-treatedsilica produced from the same base slurry (example CE-A.1) indicatesthat this treatment results in a desirable reduction in Mooneyviscosity, a desirable increase in toughness and a desirable decrease inDIN abrasion loss. The former is predictive of an improvement inprocessability while the latter two would predict an improvement inreinforcement leading to such things as improved treadwear. A comparisonof the treated silicas containing both the maleinized polybutadiene andmercaptopropylsilane treatment (examples A.3A and A.5A) to the inventivesilicas containing only the maleinized polybutadiene treatment (examplesA.2A and A.4A) as well as the non-treated silica produced from the samebase slurry (example CE-A.1A) indicates that in addition to the abovebenefits this combination of treatment also provides a desirableincrease in 300/100% Modulus ratio, a desirable increase in delta Tan(δ) (0° C.-60° C.), and a desirable decrease in Δ G′, 0.5%-16%. Thefirst would predict a further enhancement in reinforcement leading tosuch things as improved treadwear while the latter two would predict animproved balance in traction and rolling resistance (i.e., the abilityto obtain higher traction with lower rolling resistance which wouldprovide improvements in safety and fuel efficiency).

Example B

Another precipitated silica slurry was produced through the sulfuricacid neutralization of a sodium silicate. For this product, the slurrywas filtered and washed to produce a filter cake. This filter cake wasmixed with a Cowles blade to form a solid in liquid suspension. Thepercent solids of this liquefied slurry was determined and used inEquation 2 along with the values shown for the respective treatmentmaterials in Table 5 to determine the amount of treatment applied forthe respective examples shown in Table 5.

Treatment (g)=Weight of slurry (g)*solids (wt. %/100)*Styrene MaleicAnhydride Copolymer (phs/100).  Equation 2:

TABLE 5 Treatment Amount of Styrene Maleic Example Anhydride Copolymer*,phs CE-B.1 (Comparative) None B.2 15 B.3 30 *Cray Valley's SMA ® 1000 HSolution (ammonia salt, ~36% Active Solids, M_(n) = 2000, M_(w) = 5500)phs = parts per hundred of solids

The respective treatment materials were added and mixed with a Cowlesblade for a minimum of 10 minutes. This treated slurry was than dried ina Niro spray drier (inlet temperature about 400° C.; outlet temperatureabout 105° C.). The moisture of the spray dried powders was in the 4-7weight percent range. The spray dried powders were granulated using anAlexanderwerk WP 120×40 Roller Compactor using a feed screw speed of54.5 rpm, a roll compactor speed of 4.6 rpm, a crusher speed of 55.0rpm, a screen gap of 1.5 mm, a vacuum pressure of 26.2 BAR and at agranulation pressure of 20 BAR. The physical and chemical properties areshown in Table 6. The higher carbon content for the treated silicas B.2and B.3 confirms that the final products contain Styrene MaleicAnhydride Copolymer and that the amount retained increases with theamount added.

TABLE 6 Physical and Chemical Properties CTAB, BET, Carbon, ExampleTreatment Description m²/g m²/g wt. % CE-B.1 None (Comparative) 163 159<0.2 B.2 15 phs Styrene Maleic Anhydride 160 125 3.1 Copolymer (SMA1000) B.3 30 phs Styrene Maleic Anhydride 172 119 4.5 Copolymer (SMA1000)

Model Passenger Tread Formulation II

The model passenger tread formulations used to compare the example Binventive and comparative silicas are shown in Table 7. A BrabenderElectronic Plasti-Corder® Prep Mixer equipped with a 350/420 ml volumemixing head containing Banbury blades as well as an oil heated with heatexchanger and a Farrel 12 inch two-roll rubber mill were used for mixingthe ingredients following ASTM D3182-89. The formulations were mixedusing two non-productive passes and sheeted off between each pass to0.085 inches (2.16 mm). The material was allowed to cool for at leastone hour between passes and followed by a mill finish on a two-rollmill.

For the first pass, the mixer speed was adjusted to 70 rpm, the mixertemperature adjusted to 85° F. and both the solution SBR, BUNA VSL5228-2, and BR, BUDENE 1207 polymers were added to the mixer. After 30seconds into the mix cycle approximately half of the test silica and theSi 69 was added to the mixer. After another 30 seconds into the mixcycle, the remaining approximately one half of the test silica and theSUNDEX 8125 was added to the mixer. After another 30 seconds into themix cycle, the ram was raised and the chute swept, i.e., the covering onthe entry chute was raised and any material that was found in the chutewas swept back into the mixer and the ram lowered. From 120 seconds intothe mix cycle forward the mixer speed was adjusted to reach and/ormaintain a temperature of 320° F.+/−5° F. for over a 180 secondtimeframe. The first pass was dropped at a temperature of 320° F.+/−5°F. after approximately 300 seconds of total mix time.

For the second pass the mixer speed was adjusted to 70 rpm, the mixertemperature was adjusted to 85° F. and the cooled 1^(st) passMasterbatch and the KADOX-720C surface treated zinc oxide were added tothe mixer. After 30 seconds into this second mix cycle the combinationof Rubber grade stearic acid, Stangard SANTOFLEX 13 and SUNPROOFImproved were added to the mixer. After another 30 seconds into thissecond mix cycle the ram was raised and the chute swept. From 90 secondsinto this second mix cycle forward the mixer speed was adjusted to reachand/or maintain a temperature of 320° F.+/−5° F. for over a 570 secondtimeframe. This second pass was dropped at a temperature of 320° F.+/−5°F. after approximately 660 seconds of total mix time.

The RM sulfur, SANTOCURE CBS, and the DPG were blended into the cooledfirst pass Masterbatch on a two-roll rubber mill. Milling was done forapproximately 5 minutes performing 5 side cuts and 5 end passes.

TABLE 7 Model Passenger Tread Formulation II Example CE- B.1A B.2A B.3AB.3B B.2B B.3C Silica component CE-B.1 B.2 B.3 B.3 B.2 B.3 Weight(Grams) Pass 1 VSL 5228-2 123.83 123.51 123.51 123.29 120.19 120.19 BR1207 30.03 29.95 29.95 29.90 29.15 29.15 Silica 48.04 52.11 52.11 52.0250.71 50.71 Si-69 7.69 7.46 7.46 Silica 48.04 52.11 52.11 52.02 50.7150.71 Sundex 8125 6.01 5.99 5.99 5.98 5.83 5.83 TN Total Grams: 263.63263.67 263.67 263.21 264.05 264.05 Pass 2 Master Batch 263.63 263.67263.67 263.21 264.05 264.05 Zinc Oxide 3.00 2.99 2.99 2.99 2.91 2.91(KADOX 720C) Stearic Acid 1.20 1.20 1.20 1.20 1.17 1.17 SANTOFLEX 2.402.40 2.40 2.39 2.33 2.33 13 SUNPROOF 1.80 1.80 1.80 1.79 1.75 1.75Improved Subtotal 8.41 8.39 8.39 8.37 8.16 8.16 Grams: Total Grams:272.03 272.05 272.05 271.58 272.21 272.21 Mill Finish Master Batch272.03 272.05 272.05 271.58 272.21 272.21 RM Sulfur 1.68 1.68 1.68 2.391.63 1.63 CBS 2.04 2.04 2.04 3.59 1.98 1.98 DPG 2.40 2.40 2.40 0.60 2.332.33 Subtotal 6.13 6.11 6.11 6.58 5.95 5.95 Grams: Total Grams: 278.16278.16 278.16 278.16 278.16 278.16

Stress/Strain test specimens were cured for 30″ at 150° C. while allother test specimens were cured for 40″ at 150° C. Specimen preparationand testing were performed using the procedures and equipment shown inpart 2. The compound performance properties are shown in Table 8. Acomparison of the treated silicas containing only the Styrene MaleicAnhydride Copolymer treatment (examples B.2A and B.3A) without in-situcoupling agent to the non-treated silica produced from the same baseslurry (example CE-B.1A) combined with an in-situ coupling agent(indicative of the current art) (Examples B.2A and B.3A versus CE-B.1Arespectively) indicates that this treatment results in a desirableincrease in Scorch Time (TS2), a desirable decrease in Cure Time (TC90),a desirable increase in Tensile and Toughness, a desirable decrease inboth G′@−30° C. and G′(−30° C.)/G′(60° C.), and a desirable increase inG′@ 1.0%. These would predict an improvement in workability,productivity, reinforcement, improved ice traction with acceptable wettraction and stiffness (related to improved handling). The dataindicates that optimized treatment levels are required to get the bestbalance of properties. A comparison of Example B.3B with CE-B.1A, B.2Aand B.3A demonstrate that compound formulation optimization (i.e., curepackage adjustments in sulfur, CBS and DPG) can provide a furtherbalancing of properties. A comparison of Examples B.2B and B.3C comparedto CE-B.1A, B.2A and B.3A indicate that the silicas treated with StyreneMaleic Anhydride Copolymer combined with an in-situ coupling agent(indicative of the current art) still provides the desirable benefitsdiscussed above.

TABLE 8 Model Passenger Tread Formulation Results Example CE-B.1A B.2AB.3A B.3B B.2B B.3C Silica, phr 80.0 87.0 87.0 87.0 87.0 87.0 Si-69, phr6.4 6.4 6.4 RM Sulfur, phr 1.40 1.40 1.40 2.00 1.40 1.40 CBS, phr 1.701.70 1.70 3.00 1.70 1.70 DPG, phr 2.00 2.00 2.00 0.50 2.00 2.00 ScorchTime (TS2), minutes 2.7 4.9 1.0 0.5 5.6 6.1 Cure Time (TC90), minutes35.2 31.0 28.9 32.9 36.8 31.3 Stress Strain Tensile, MPa 13.8 16.5 12.815.3 16.7 14.2 Toughness (Tensile * 4194 9965 8214 8327 6285 5270Elongation), MPa * % RDS - temp sweep, 1 Hz, 2% strain G′@−30° C., MPa38.0 44.7 5.8 58.2 35.0 39.4 G′(−30° C.)/G′(60° C.) 19.2 18.2 2.4 22.317.3 17.1 RDS - strain sweep, 30 C., 1 Hz G′@ 1.0%, MPa 2.742 3.4364.144 3.953 2.544 3.240 SMA = Styrene Maleic Anhydride Copolymer (SMA ®1000)

Example C

Another precipitated silica slurry was produced through the sulfuricacid neutralization of a sodium silicate. For this product, the slurrywas filtered and washed to produce a filter cake. This filter cake wasmixed with a Cowles blade to form a solid in liquid suspension. Thepercent solids of this liquefied slurry was determined and used inEquation 2 above along with the values shown for the respectivetreatment materials in Table 9 to determine the amount of treatmentapplied for the respective examples shown in Table 9. The respectivetreatment materials were added and mixed with a Cowles blade for aminimum of 10 minutes. This treated slurry was than dried in a Nirospray drier (inlet temperature about 400° C.; outlet temperature about105° C.). The moisture of the spray dried powders was in the 4-7 weightpercent range. The spray dried powders were granulated using anAlexanderwerk WP 120×40 Roller Compactor using a feed screw speed of54.5 rpm, a roll compactor speed of 4.6 rpm, a crusher speed of 55.0rpm, a screen gap of 1.5 mm, a vacuum pressure of 26.2 BAR and at agranulation pressure of 20 BAR. The physical and chemical properties areshown in Table 10. The higher carbon content for the inventive silicasC.2 and C.3 confirms that the final products contain Styrene MaleicAnhydride Copolymer and that the amount retained increases with theamount added.

TABLE 9 Treatment Amount of Styrene Maleic Anhydride Example Copolymer*,phs CE-C.1 (Comparative) None C.2 15 C.3 30 *Cray Valley's SMA ® 3000 HSolution (ammonia salt, ~15% Active Solids, M_(n) = 3800, M_(w) = 9500)phs = parts per hundred of solids

TABLE 10 Physical and Chemical Properties CTAB, BET, Carbon, ExampleTreatment Description m²/g m²/g wt. % CE-C.1 None (Comparative) 178 188<0.2 C.2 15 phs Styrene Maleic Anhydride 179 164 3.1 Copolymer (SMA3000) C.3 30 phs Styrene Maleic Anhydride 183 151 5.2 Copolymer (SMA3000)

Model Passenger Tread Formulation II

The model passenger tread formulations used to compare the example Cinventive and comparative silicas are shown in Table 11. The mixing,curing, specimen preparation and testing procedures were the same asdescribed in example B. The compound performance properties are shown inTable 12. A comparison of the inventive silicas containing only theStyrene Maleic Anhydride Copolymer treatment (examples C.2 and C.3)without in-situ coupling agent to the non-treated silica produced fromthe same base slurry (example CE-C.1) combined with an in-situ couplingagent (indicative of the current art) (compounds 11.2 and 11.3 versus11.1 respectively) indicates that this treatment results in a desirableincrease in Scorch Time (TS2), while maintaining an acceptable Cure Time(TC90), a desirable increase in Tensile and Toughness, a desirabledecrease in G′(−30° C.)/G′(60° C.), and a desirable increase in G′@1.0%. These would predict an improvement in workability, productivity,reinforcement, ice traction/wet traction balance and stiffness (relatedto improved handling). The data indicates that optimized treatmentlevels are required to get the best balance of properties. A comparisonof examples C.3B with CE-C.1A, C.2A and C.3A indicate that compoundformulation optimization (i.e. cure package adjustments in sulfur, CBSand DPG) can provide a further balancing of properties. A comparison ofExamples C.2B and C.3C to CE-C.1A, C.2A and C.3A indicate that thetreated silicas containing only the Styrene Maleic Anhydride Copolymertreatment combined with an in-situ coupling agent (indicative of thecurrent art) still provides the desirable benefits discussed above.

TABLE 11 Model Passenger Tread Formulation II Example CE-C.1A C.2A C.3AC.3B C.2B C.3C Silica component CE-C.1 C.2 C.3 C.3 C.2 C.3 Weight(Grams) Pass 1 VSL 5228-2 123.83 123.51 123.51 123.29 120.19 120.19 BR1207 30.03 29.95 29.95 29.90 29.15 29.15 Silica 48.04 52.11 52.11 52.0250.71 50.71 Si-69 7.69 7.46 7.46 Silica 48.04 52.11 52.11 52.02 50.7150.71 Sundex 8125 6.01 5.99 5.99 5.98 5.83 5.83 TN Total Grams: 263.63263.67 263.67 263.21 264.05 264.05 Pass 2 Master Batch 263.63 263.67263.67 263.21 264.05 264.05 Zinc Oxide 3.00 2.99 2.99 2.99 2.91 2.91(720C) Stearic Acid 1.20 1.20 1.20 1.20 1.17 1.17 Santoflex 13 2.40 2.402.40 2.39 2.33 2.33 Sunproof 1.80 1.80 1.80 1.79 1.75 1.75 ImprovedSubtotal 8.41 8.39 8.39 8.37 8.16 8.16 Grams: Total Grams: 272.03 272.05272.05 271.58 272.21 272.21 Mill Finish Master Batch 272.03 272.05272.05 271.58 272.21 272.21 RM Sulfur 1.68 1.68 1.68 2.39 1.63 1.63 CBS2.04 2.04 2.04 3.59 1.98 1.98 DPG 2.40 2.40 2.40 0.60 2.33 2.33 Subtotal6.13 6.11 6.11 6.58 5.95 5.95 Grams: Total Grams: 278.16 278.16 278.16278.16 278.16 278.16

TABLE 12 Model Passenger Tread Formulation Results Example CE-C.1A C.2AC.3A C.3B C.2B C.3C Silica, phr 80.0 87.0 87.0 87.0 87.0 87.0 Si-69, phr6.4 6.4 6.4 RM Sulfur, phr 1.40 1.40 1.40 2.00 1.40 1.40 CBS, phr 1.701.70 1.70 3.00 1.70 1.70 DPG, phr 2.00 2.00 2.00 0.50 2.00 2.00 ScorchTime (TS2), 2.9 4.2 5.3 0.6 3.1 3.9 minutes Cure Time (TC90), 34.5 41.535.6 33.2 31.7 33.8 minutes Tensile, MPa 15.3 16.2 15.7 15.4 14.3 16.6Toughness (Tensile * 5610 10858 11730 9734 4746 6946 Elongation), MPa *% RDS - temp sweep, 1 Hz, 2% strain G′@−30° C., Mpa 49.350 86.919 78.69194.384 60.912 72.326 G′(30° C.)/G′(60° C.) 24.023 18.311 21.294 22.29322.147 18.560 RDS - strain sweep, 30 C., 1 Hz G′ @ 1.0%, MPa 2.760 9.4497.359 7.152 3.726 6.353 SMA = Styrene Maleic Anhydride Copolymer (SMA ®3000)

Example D

Water (75.0 liters) was added to the 150 L reactor tank and heated to72.0° C. via indirect steam coil heat. Sodium silicate (2.5 L) was addedat a rate of 560 mL/min. The temperature was adjusted as necessary to72.0° C. via indirect steam coil heating and the precipitation step wasinitiated. The 150 liter reactor was agitated via the main tankagitator. The main agitator was left on and a simultaneous additionprecipitation step was started. Sodium silicate (50.4 liters) and 3.2liters of sulfuric acid were added simultaneously over a period of 90minutes. The sodium silicate was added via an open tube near the bottomof the tank at a rate of 560 ml/min and the sulfuric acid was addeddirectly above the secondary high speed mixer blades. The acid additionrate averaged 36.0 ml/min over the course of the 90 minute simultaneousaddition step.

At the end of the simultaneous addition step, a 100 minute age step wasinitiated and the temperature was raised to 85° C. The pH of thesolution was adjusted to 8.5 using sulfuric acid. SILQUEST® A-1891(3-mercaptopropyltriethoxysilane, available commercially from Momentive)was added into the reactor at 5.5 PHS (744.3 grams). Thenpolyethyleneoxide silane (PEO silane; SILQUEST A-1230) was added at 6PHS to the reactor. The reaction mixture completed ageing under stirringfor the remainder of the 100 minutes. The temperature was maintained at85° C. After the age step was completed, sulfuric acid was added toreach a final batch pH of 4.8.

The mixture was pumped into a filter press and washed until theconductivity of the rinse water measured less than 1000 microsiemens.The resulting filter cake was reslurried with water to form a pumpableslurry and spray dried using a Niro spray drier (Utility Model 5 withType FU-1 rotary atomizer, Niro Inc.). The spray dried powder wasgranulated using an Alexanderwerk WP120X40 Roller Compactor with thefollowing conditions; screw speed=55 rpm, roller speed 4.5 rpm, crusherspeed=55 rpm, hydraulic pressure=25 bar and screen size ˜7 mesh. Thephysical properties of the synthesized silicas are summarized in Table13.

TABLE 13 Physical and Chemical Properties CTAB, BET, Carbon, ExampleTreatment Description m²/g m²/g wt. % CE-D.1 None (Comparative) 160 160<0.2 D.2 PEO treated silica 133 157 2.4 and 5.5 PHS silane

The model passenger tread formulations used to compare the example Dinventive and comparative silicas are shown in Table 14. The highercarbon content for the inventive silica indicates that the PEO silanehas in fact been retained on the silica surface.

TABLE 14 Model Passenger Tread Formulation Results MODEL PASSENGERFORMULATION III Example CE-D.1A D.2A Silica component CE-D.1 D.2 Silica,phr 80.0 80.0 Si-69, phr 7.0 0.0 RM Sulfur, phr 1.4 2.0 CBS, phr 1.7 3.0DPG, phr 2.0 0.5 Scorch Time (TS2), minutes 3.2 4.9 Cure Time (TC90),minutes 19.2 28.2 M_(H)-M_(L) 21.1 13.8 Tensile, MPa 17.7 12.5Elongation 328.0 249.0 Hardness, Shore A 58.0 60.0 Toughness (Tensile *Elongation), MPa * % 5806 3113 RDS - temp sweep, 1 Hz, 2% strain Tandelta 60° C. 0.066 0.067 Tan delta 0° C. 0.366 0.466 Delta tan delta 0°C. − 60° C. 0.301 0.399 RDS - strain sweep, 30 C., 1 Hz G′@ 0.5%, MPa2.1 2.2

A comparison between the comparative silica formulation CE-D.1A and thesilica formulation D.2A shows a reduction in elongation and an increasein hardness.

Alternatively, the PEO treated silica was tested in a naturalrubber-based truck tire tread compound. PEO type materials are commonlyused as both an activator and a processing aid in rubber compounding.

The following ingredients listed in Table 15 in amounts of parts perhundred parts of rubber by weight (phr) were added in the orderdescribed to a polyethylene bag held erect in a 500-milliliter (mL)plastic cup.

TABLE 15 Ingredients combined into plastic bag for natural rubber mixMaterial Amount (phr) Processing oil* 5.0 Zinc oxide 4.0 SANTOFLEX 13(6-PPD) 2.5 Stearic acid 2.0 STANGARD ® TMQ** 2.0 SUNPROOF Improved 1.0*VIVATECH ® 500 aromatic hydrocarbon processing oil, distributed byHansen-Rosenthal KG **Stangard TMQ distributed by Harwick Standard

The remaining ingredients, shown in Table 16, were weighed and added toa paper cup.

TABLE 16 Ingredients combined into paper cup for natural rubber mixMaterial Amount (phr) Test Silica Filler 50.0 Carbon Black N-220* 3.0Silane (if not pre-reacted) 6.0 *Sid Richardson Carbon and EnergyCompany

A 1.89 liter (L) Kobelco internal mixer (Model “BR00”) was used formixing the various ingredients. Immediately prior to adding the batchingredients to the mixer, 800 grams (g) of CV-60 grade natural rubberwas put through the mixer to clean it of any residue of previous runsand increase the temperature to about 93° C. (200° F.). After removingthe rubber, the mixer was cooled to about 65° C. (150° F.) before addingthe ingredients to produce the rubber test sample. A rubber compositionis prepared using the test filler, the following other enumeratedingredients in Table 17 and the following procedure.

TABLE 17 Model NR Truck Tread Compound CE-D.1B Ingredient Amount (PHR)D.2B Pass 1 Clarimer L CV60 100.0 100.0 Carbon Black N-220 3.0 3.0Silica Addition 1 25.0 25.0 Silane (Si-266) 6.0 0.0 Silica Addition 225.0 25.0 Vivatech 500 5.0 5.0 TOTAL 164.0 158.0 Pass 2 Masterbatch164.0 100.0 Zinc Oxide 4.0 3.0 Stearic Acid 2.0 25.0 Santoflex 13(6-PPD) 2.5 25.0 Stangard TMQ 2.0 5.0 Sunproof Improved 1.0 158.0 TOTAL175.5 169.5 STOCK SHEETED OFF AT APPROXIMATELY .085″ STOCK COOLED BEFOREMILL FINISH AFTER A MINIMUM OF ONE HOUR REST MILL FINISH Masterbatch175.5 169.5 RM Sulfur 2.0 2.0 CBS 3.0 3.0 DPG 0.5 0.5 TOTAL 181.0 175.0

The first pass was initiated by adding the rubber to the mixer andmixing at 30 rpm. The rotor speed was maintained at 30 rpm and 3.0 phrcarbon black was added. After one minute, half of the test filler andall of the silane Si-266 (Bis [3-(triethoxysilyl) propyl] disulfide,available commercially from Evonik) was added with the remainder of thetest filler being added one minute later. The Sundex 8125 was added withthe second part of test filler. At three minutes, the ram was raised andthe chute swept, i.e., the covering on the entry chute was raised andany material that was found in the chute was swept back into the mixer.The speed of the mixer was increased to 70 rpm. The contents in themixer were mixed for an additional two minutes to achieve a maximumtemperature in the range of from 145 to 150° C. (293 to 302° F.) and tocomplete the first pass in the mixer. Depending upon the type of sample,the rotor speed of the mixer may be increased or decreased after 4minutes to achieve a temperature in the foregoing range within thespecified mixing period. The material was removed from the mixer.

After completing the first pass, the removed material was weighed andsheeted in a Farrel 12 inch, two-roll rubber mill at 2.032 mm±0.127 mm(0.080 inch±0.005 inch). The resulting milled stock was used for thesecond pass in the mixer. The second pass was initiated by adding thefirst pass stock to the mixer operating at 60 rpm. After one minute, thepre-weighed zinc oxide, stearic acid, Santoflex 13, Stangard TMQ andSunproof Improved were added to the mixer. After an additional minute,the ram was raised and the chute swept. The mixing speed was decreasedto 30 rpm. The second pass was completed by mixing the stock anadditional 3.0 minutes while maintaining the temperature at or below135° C. (257° F.) to 140° C. (284° F.).

A Farrel 12 inch, two-roll rubber mill was heated to approximately 60°C. (140° F.). The stock from the second pass of Part B was fed into therunning mill with a nip setting of 2.032 mm±0.127 mm (0.080 inch±0.005inch). The RM sulfur, CBS and DPG were added to the mill and blendedtogether. The total mill time was about five minutes with 5 side cutsand 5 end rolls. The resulting sheet was placed on a flat surface untilthe temperature of the sheet reached room temperature. Typically, thesheet cooled within about 30 minutes. The sheet stock collected off themill was placed on a flat clean surface. Using a stencil, a rectangularsample 203.2 mm×152.4 mm (8 inches×6 inches) was cut from the sheetstock. The sample was conditioned, i.e., stored between cleanpolyethylene sheets and maintained for 15 to 18 hours at a temperatureof 23°±2° C., and a relative humidity of 50%±5%.

After conditioning, the sample was placed in a 203.2 mm×152.4 mm×2.286mm (8 inches×6 inches×0.09 inch) standard frame machine steelcompression mold having a polished surface. The sample was cured in a 61centimeter×61 centimeter (24 inches×24 inches) 890 kilonewton (100 ton)4-post electrically heated compression press, for T90, i.e., the time ittakes for 90 percent of the cure to occur, in accordance with ASTMD-2084, plus 5 minutes at 150° C. (302° F.) under a pressure of 13.79megapascals (2000 pounds per square inch). Typically, curing wascompleted within about 10 minutes. The resulting cured rubber sheet wasremoved from the mold and maintained for 15 to 18 hours at a temperatureof 23°±2° C. (73.4±3.6° F.), and a relative humidity of 50%±5% prior totesting in Part D.

Testing was performed in accordance with ASTM D 412-98a—Test Method A.Dumbbell test specimens were prepared using Die C. An Instron model 4204with an automated contact extensiometer for measuring elongation wasused. The cross-head speed was found to equal 508 mm/min. Allcalculations were done using the Series IX Automated Materials Testingsoftware supplied by the manufacturer. The Reinforcement Index equalsthe Tensile Stress at 300% elongation (in MPa) divided by the TensileStress at 100% elongation (in MPa). When the samples were prepared usingthe Standard Compounding Protocol, the results were reported as theStandard Reinforcement Index. The compounding results are shown in Table18.

TABLE 18 Model NR Truck Tread Results MODEL TRUCK TREAD I ExampleCE-D.1B D.2B Silica component CE-D.1 D.2 Silica, phr 50.0 50.0 RMSulfur, phr 2.0 2.0 CBS, phr 3.0 3.0 DPG, phr 0.5 0.5 Scorch Time (TS2),minutes 3.1 1.8 Cure Time (TC90), minutes 5.7 3.9 M_(L)(1 + 4), MU 75.169.8 M_(H)-M_(L) 29.0 31.0 Tensile, MPa 32.8 31.4 Elongation 580.0 552.0Hardness, Shore A 57.0 60.0 Toughness (Tensile * Elongation), MPa * %19024.0 17333.0 RDS - temp sweep, 1 Hz, 2% strain Tan delta 60° C. 0.0360.059 Tan delta 0° C. 0.083 0.101 Delta tan delta 0° C. − 60° C. 0.0470.043 RDS - strain sweep, 30 C., 1 Hz G′@ 0.5%, MPa 2.7 2.8 *comparativeexample is based on a silica produced following the exact recipe ofexample D.2 except that stearic acid was used at 6 PHR instead of thePEO silane.

In natural rubber, the inventive silica D.2B shows a characteristicreduction in cure time that is typical for the use of glycol basedprocessing aids. The presence of the polymeric material on the silicasurface shows a reduction in Mooney viscosity relative to thecomparative example. The crosslink density and the resulting hardness ofthe resulting inventive silica compound are also increased despiteidentical curing conditions.

Example E

A hyperbranched acrylic polymer according to the present invention wasprepared from the following mixture of ingredients as described in Table19:

TABLE 19 Acrylic Polymer Preparation Ingredients Parts by Weight (grams)Charge I butyl acrylate 2237.2 butyl methacrylate 1029.3 hydroxyethylacrylate 470.1 α-methylstyrene 470.1 acrylic acid 329.1 Allylmethacrylate 164.60 di-t-amyl peroxide 235.20 ethylene glycol monobutylether 940.30 Charge II di-t-amyl peroxide 150.0

A 300 cm³ electrically heated continuous stirred tank reactor with aninternal cooling coil was filled with ethylene glycol monobutyl etherand the temperature was adjusted to 200° C. Charge I from Table 19 wasfed to the reactor from a feed tank at 100 cm³/minute, resulting in aresidence time of three minutes. The reactor was kept volumetricallyfull at a pressure of 400-600 psi. The temperature was held constant at200° C. The reactor output was drained to a waste vessel for the firstnine minutes and was then diverted to a 3000 cm³ continuous stirred tankreactor fitted with a pressure relief valve set to vent at 35 psi. Atthis point, Charge II was fed to the second reactor at a rate of 0.95cm³/minute. The contents of the second reactor were maintained at 170°C. When 1500 cm³ had been added to the second reactor, the outlet valvewas opened and the resin was fed to a collection vessel at a rate thatmaintained a constant fill level, resulting in a 15 minute residencetime. The resulting hyperbranched acrylic polymer had a solids contentof 80.9%. A hyperbranched acrylic polymer aqueous dispersion wasprepared from the following mixture of ingredients as described in Table20.

TABLE 20 Dispersion Preparation Ingredients Parts by Weight (grams)Charge I Hyperbranched acrylic polymer of 1237.5 Example 1 n-butylmethacrylate 23.72 Dimethyl ethanolamine 4.96 SOLSPERSE ® 46000 (adispersant 3.08 available commercially from Lubrizol) PrecipitatedSilica 276.69 Deionized Water 790.54 Deionized Water 205.00

The materials were milled in a mini-basket media mill. A portion of thesecond water addition was added during milling to ensure goodviscosity/mixing and the batch was run for 90 minutes before beingkicked off. The properties of the dried silica are shown in Table 21.

TABLE 21 Properties Of Silica And Polymer Treated Silica BET, ExampleTreatment Description CTAB, m²/g m²/g Carbon, wt. % CE-E.1 None(Comparative) 176.0 195.0 0.0 E.2 Polymer Treated Silica 154.0 47.0 24.0

The material was mixed in passenger tread I (previously described) andthe properties are detailed in Table 22. The higher carbon content forthe inventive silica E.2 indicates that the polymer has in fact beenretained on the silica surface.

TABLE 22 Properties Of Rubber Compounds Model Passenger Formulation IExample CE-E.1A E.2A Silica component CE-E.1 E.2 Silica, phr 80.0 86.4Si-69, phr 10.0 0.0 RM Sulfur, phr 1.4 2.0 CBS, phr 1.7 3.0 DPG, phr 2.00.5 Scorch Time (TS2), minutes 3.4 14.7 Cure Time (TC90), minutes 30.734.9 M_(L)(1 + 4), MU 81.0 50.0 M_(H)-M_(L) 16.48 10.8 Tensile, MPa 18.29.8 Elongation 364.0 778 Hardness, Shore A 63.0 59.0 Toughness(Tensile * Elongation), MPa * % 6625.0 7624.0 RDS - temp sweep, 1 Hz, 2%strain Tan delta 60° C. 0.094 0.130 Tan delta 0° C. 0.381 0.390 Deltatan delta 0° C. − 60° C. 0.287 0.260 RDS - strain sweep, 30 C., 1 Hz G′@0.5%, MPa 3.70 3.43

In this example, the acrylic polymer treated silica filled rubbedcompound E.2A shows a 31 Mooney unit reduction in viscosity relative tothe comparative silica as well as a reduction in the low strain G′.Furthermore, the silica shows improved toughness relative to thecomparative silica.

Example F

Approximately 2000 g of an approximately 7% solids silica slurry wasadded to a 5 L 3-neck flask under mechanical stirring. The reactortemperature was set to 87° C. and 3-mercaptopropyltriethoxysilane wasadded slowly at 5.5 wt. % relative to the SiO₂ solids. After theaddition of silane was complete, Genflo 3810, a carboxylated SBR latexwas added to the reactor at 6 wt. % relative to SiO₂ solids. The pH ofthe slurry was adjusted to 4.5 using concentrated sulfuric acid. Theresulting product was washed on funnels using DI water. The material wasreslurried to 12% solids with deionized water. Then the slurry was driedusing a mini Buchi spray drier. The inlet temperature was set at180-185° C., the outlet temperature at 90-92° C. The aspirator was setat 80% and the pump at 22%. The air pressure was 80 psi. The propertiesof the dried silica are shown in Table 23.

TABLE 23 Properties Of Silica And Polymer Treated Silica BET, ExampleTreatment Description CTAB, m²/g m²/g Carbon, wt. % CE-F.1 None(Comparative) 176.0 195.0 0.0 F.2 Latex Treated Silica 159.0 159.0 3.4

The components in Table 24 were blended and cured using techniques wellknown in the tire tread compounding art. The properties of the curedrubber compounds are shown in Table 25. The higher carbon content forthe inventive silica F.2 indicates that the latex has in fact beenretained on the silica surface

TABLE 24 Rubber Compound Formulations* Example CE-F.1A F.2A Silicacomponent CE-F.1 F.2 Pass 1 VSL 5228-2 122.12 124.09 BR 1207 29.61 30.09Silica 47.38 52.00 Si-69 8.29 — Silica 47.38 52.00 Sundex 8125 TN 5.926.02 Zinc Oxide — 3.01 Stearic Acid — 1.20 Santoflex 13 — 2.41 SunproofImproved — 1.81 Total Grams: 260.71 272.61 Pass 2 Master Batch 260.71 —Zinc Oxide (720C) 2.96 — Stearic Acid 1.18 — Santoflex 13 2.37 —Sunproof Improved 1.78 — Subtotal Grams: 8.29 — Total Grams: 269.01 —Mill Finish Master Batch 269.01 272.61 RM Sulfur 1.66 2.41 CBS 2.01 3.61DPG 2.37 0.60 Subtotal Grams: 6.04 6.62 Total Grams: 275.05 279.23*Mixed on Brabender Plasticorder equipped with 2 wing rotors

TABLE 25 Properties Of Rubber Compounds MODEL PASSENGER FORMULATION IExample CE-F.1A F.2A Silica component CE-F.1 F.2 Silica, phr 80.0 80.0Si-69, phr 7.0 0.0 RM Sulfur, phr 1.4 2.0 CBS, phr 1.7 3.0 DPG, phr 2.00.5 M_(L)(1 + 4), MU 79.4 96.9 M_(H)-M_(L) 24.8 23.2 Tensile, MPa 19.016.6 Elongation 529.0 332.0 Hardness, Shore A 64.0 65.0 Toughness(Tensile * Elongation), MPa * % 10051 5511 RDS - temp sweep, 1 Hz, 2%strain Tan delta 60° C. 0.090 0.078 Tan delta 0° C. 0.315 0.331 Deltatan delta 0° C. − 60° C. 0.225 0.298 RDS - strain sweep, 30 C., 1 Hz G′@0.5%, MPa 4.04 2.5

In this example, the latex treated silica reduces the elongation of thecompound F.2A relative to the comparative silica filled compoundCE-F.1A. The rolling resistance is reduced relative to the comparativesilica compound and the wet traction is greater. The low strain G′ isalso reduced indicating a reduction in filler-filler interaction for thelatex treated silica.

Although the present invention has been described with references tospecific details of certain embodiments thereof, it is not intended thatsuch details should be regarded as limitations upon the scope of theinvention except in so far as they are included in the claims.

What is claimed is:
 1. A rubber composition comprising a treated filler,produced by: (a) treating a slurry comprising untreated filler, whereinsaid untreated filler has not been previously dried, with a treatingcomposition comprising a treating agent, thereby forming a treatedfiller slurry; and (b) drying said treated filler slurry to producetreated filler, wherein said treating agent comprises a polymercomprising (i) at least one first group that interacts with saiduntreated filler and (ii) at least one second group that interacts witha rubber matrix into which said treated filler is incorporated.
 2. Therubber composition of claim 1, wherein the treating composition furthercomprises a coupling agent comprising an organosilane selected from thegroup consisting of (4-chloromethyl-phenyl) trimethoxysilane,(4-chloromethyl-phenyl) triethoxysilane,[2-(4-chloromethyl-phenyl)-ethyl] trimethoxysilane,[2-(4-chloromethyl-phenyl)-ethyl]triethoxysilane,(3-chloro-propenyl)-trimethoxysilane,(3-chloro-propenyl)-triethoxysilane, (3-chloro-propyl)-triethoxysilane,(3-chloro-propyl)-trimethoxysilane, trimethoxy-(2-p-tolyl-ethyl)silane,triethoxy-(2-p-tolyl-ethyl)silane, and combinations thereof.
 3. Therubber composition of claim 1, wherein the rubber composition comprisesnatural rubber.
 4. The rubber composition of claim 1, wherein the rubbercomposition is a rubber compounding master batch.
 5. The rubbercomposition of claim 1, wherein said untreated filler is chosen fromaluminum silicate, silica gel, colloidal silica, precipitated silica,and mixtures thereof.
 6. The rubber composition of claim 1, wherein thefiller comprises precipitated silica.
 7. The rubber composition of claim1, wherein the polymer is selected from an acrylic polymer, a styrenebutadiene latex, a natural rubber latex, or combinations thereof.
 8. Therubber composition of claim 7, wherein the acrylic polymer is selectedfrom an acrylic random copolymer, an acrylic comb polymer, an acrylicblock copolymer, a hyperbranched acrylic polymer, or combinationsthereof.
 9. The rubber composition of claim 8, wherein the hyperbranchedacrylic polymer at least partially encapsulates the treated filler. 10.The rubber composition of claim 1, wherein the at least one first groupis selected from an ester, carboxylic acid, imide, anhydride, diacid,lactone, oxirane, isocyanate, alkoxysilane, hydrolysis products thereof,salts thereof, or combinations thereof.
 11. The rubber composition ofclaim 1, wherein the at least one second group is selected from formyl,keto, thiol, sulfido, halo, amino, alkenyl, alkynyl, alkyl, hydrolysisproducts thereof, salts thereof, or combinations thereof.
 12. The rubbercomposition of claim 1, wherein the at least one second group isselected from hydroxyl, anhydride, oxirane, hydrolysis products thereof,salts thereof, or combinations thereof.
 13. The rubber composition ofclaim 1, wherein the treating composition further comprises anorganosilane coupling agent represented by formula (II):(R₁)_(a)(R₂)_(b)SiX_(4-a-b)  (II), wherein each R₁ is independently ahydrocarbyl group comprising 1 to 36 carbon atoms and a functionalgroup, wherein the functional group of the hydrocarbyl group is vinyl,allyl, hexenyl, epoxy, glycidoxy, (meth)acryloxy, sulfide, isocyanato,polysulfide, mercapto, or halogen; each R₂ is independently ahydrocarbyl group having from 1 to 36 carbon atoms or hydrogen; X isindependently halogen or alkoxy having 1 to 36 carbon atoms; a is 0, 1,2, or 3; b is 0, 1, or 2; (a+b) is 1, 2, or 3; provided that when b is1, (a+b) is 2 or
 3. 14. The rubber composition of claim 13, wherein thetreating composition further comprises an organosilane different fromthe organosilane represented by formula (II).
 15. The rubber compositionof claim 1, wherein the treating composition further comprises anon-coupling agent that is different from the treating agent and whereinthe non-coupling agent that is different from the treating agent is oneor more of a biopolymer, fatty acid, organic acid, polymer emulsion,polymer coating composition, and combinations thereof.
 16. The rubbercomposition of claim 1, wherein the treating composition furthercomprises a non-coupling agent selected from an anionic surfactant, anonionic surfactant, an amphoteric surfactant, and combinations thereof,present in an amount of from greater than 1% to 25% by weight based onthe weight of untreated filler.
 17. The rubber composition of claim 1,wherein the treated filler comprises treated precipitated silica; andthe treating composition further comprises: (i) at least one couplingagent, and (ii) a non-coupling agent chosen from anionic, nonionicand/or amphoteric surfactants, which is present in an amount of fromgreater than 1% to 25% by weight based on the weight of untreatedfiller.
 18. A rubber composition, rubber article, or tire treadcomprising a treated precipitated silica, produced by: (a) combining analkali metal silicate and an acid to form an untreated slurry comprisinguntreated silica, wherein said untreated silica has not been previouslydried; (b) drying the untreated slurry to produce dried precipitatedsilica; (c) forming an aqueous slurry of the dried precipitated silicawith a treating composition comprising a treating agent, and,optionally, a coupling agent and/or, optionally, a non-coupling agent toform a treated precipitated silica slurry; and (d) drying the treatedprecipitated silica slurry to produce a dried treated precipitatedsilica, wherein said treating agent comprises a polymer comprising (i)at least one first group that interacts with said untreated silica and(ii) at least one second group that interacts with a rubber matrix intowhich said treated silica is incorporated.
 19. The treated precipitatedsilica of claim 18, wherein said coupling agent of said treatingcomposition comprises an organosilane selected from the group consistingof (4-chloromethyl-phenyl) trimethoxysilane, (4-chloromethyl-phenyl)triethoxysilane, [2-(4-chloromethyl-phenyl)-ethyl] trimethoxysilane,[2-(4-chloromethyl-phenyl)-ethyl]triethoxysilane,(3-chloro-propenyl)-trimethoxysilane,(3-chloro-propenyl)-triethoxysilane, (3-chloro-propyl)-triethoxysilane,(3-chloro-propyl)-trimethoxysilane, trimethoxy-(2-p-tolyl-ethyl)silane,triethoxy-(2-p-tolyl-ethyl)silane, and combinations thereof.
 20. Thetreated precipitated silica of claim 18, wherein the polymer is selectedfrom an acrylic polymer, a styrene butadiene latex, a natural rubberlatex, or combinations thereof.
 21. The treated precipitated silica ofclaim 20, wherein the acrylic polymer is selected from an acrylic randomcopolymer, an acrylic comb polymer, an acrylic block copolymer, ahyperbranched acrylic polymer, or combinations thereof.
 22. The treatedprecipitated silica of claim 21, wherein the hyperbranched acrylicpolymer at least partially encapsulates the treated filler.
 23. Thetreated precipitated silica of claim 18, wherein the at least one firstgroup is selected from an ester, carboxylic acid, imide, anhydride,diacid, lactone, oxirane, isocyanate, alkoxysilane, hydrolysis productsthereof, salts thereof, or combinations thereof.
 24. The treatedprecipitated silica of claim 18, wherein the at least one second groupis selected from formyl, keto, thiol, sulfido, halo, amino, alkenyl,alkynyl, alkyl, hydrolysis products thereof, salts thereof, orcombinations thereof.
 25. The treated precipitated silica of claim 18,wherein the at least one second group is selected from hydroxyl,anhydride, oxirane, hydrolysis products thereof, salts thereof, orcombinations thereof.